// MIT License
//
// Copyright(c) 2023 Jordan Peck (jordan.me2@gmail.com)
// Copyright(c) 2023 Contributors
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files(the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and / or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions :
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
//
// .'',;:cldxkO00KKXXNNWWWNNXKOkxdollcc::::::;:::ccllloooolllllllllooollc:,'...        ...........',;cldxkO000Okxdlc::;;;,,;;;::cclllllll
// ..',;:ldxO0KXXNNNNNNNNXXK0kxdolcc::::::;;;,,,,,,;;;;;;;;;;:::cclllllc:;'....       ...........',;:ldxO0KXXXK0Okxdolc::;;;;::cllodddddo
// ...',:loxO0KXNNNNNXXKK0Okxdolc::;::::::::;;;,,'''''.....''',;:clllllc:;,'............''''''''',;:loxO0KXNNNNNXK0Okxdollccccllodxxxxxxd
// ....';:ldkO0KXXXKK00Okxdolcc:;;;;;::cclllcc:;;,''..... ....',;clooddolcc:;;;;,,;;;;;::::;;;;;;:cloxk0KXNWWWWWWNXKK0Okxddoooddxxkkkkkxx
// .....';:ldxkOOOOOkxxdolcc:;;;,,,;;:cllooooolcc:;'...      ..,:codxkkkxddooollloooooooollcc:::::clodkO0KXNWWWWWWNNXK00Okxxxxxxxxkkkkxxx
// . ....';:cloddddo___________,,,,;;:clooddddoolc:,...      ..,:ldx__00OOOkkk___kkkkkkxxdollc::::cclodkO0KXXNNNNNNXXK0OOkxxxxxxxxxxxxddd
// .......',;:cccc:|           |,,,;;:cclooddddoll:;'..     ..';cox|  \KKK000|   |KK00OOkxdocc___;::clldxxkO0KKKKK00Okkxdddddddddddddddoo
// .......'',,,,,''|   ________|',,;;::cclloooooolc:;'......___:ldk|   \KK000|   |XKKK0Okxolc|   |;;::cclodxxkkkkxxdoolllcclllooodddooooo
// ''......''''....|   |  ....'',,,,;;;::cclloooollc:;,''.'|   |oxk|    \OOO0|   |KKK00Oxdoll|___|;;;;;::ccllllllcc::;;,,;;;:cclloooooooo
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// c:;,''......... |         |:::/     '   |lo/        |           |      \dx|   |0/       \d|   |cc/        |'/       \......',,;;:ccllo
// ol:;,'..........|    _____|ll/    __    |o/   ______|____    ___|   |   \o|   |/   ___   \|   |o/   ______|/   ___   \ .......'',;:clo
// dlc;,...........|   |::clooo|    /  |   |x\___   \KXKKK0|   |dol|   |\   \|   |   |   |   |   |d\___   \..|   |  /   /       ....',:cl
// xoc;'...  .....'|   |llodddd|    \__|   |_____\   \KKK0O|   |lc:|   |'\       |   |___|   |   |_____\   \.|   |_/___/...      ...',;:c
// dlc;'... ....',;|   |oddddddo\          |          |Okkx|   |::;|   |..\      |\         /|   |          | \         |...    ....',;:c
// ol:,'.......',:c|___|xxxddollc\_____,___|_________/ddoll|___|,,,|___|...\_____|:\ ______/l|___|_________/...\________|'........',;::cc
// c:;'.......';:codxxkkkkxxolc::;::clodxkOO0OOkkxdollc::;;,,''''',,,,''''''''''',,'''''',;:loxkkOOkxol:;,'''',,;:ccllcc:;,'''''',;::ccll
// ;,'.......',:codxkOO0OOkxdlc:;,,;;:cldxxkkxxdolc:;;,,''.....'',;;:::;;,,,'''''........,;cldkO0KK0Okdoc::;;::cloodddoolc:;;;;;::ccllooo
// .........',;:lodxOO0000Okdoc:,,',,;:clloddoolc:;,''.......'',;:clooollc:;;,,''.......',:ldkOKXNNXX0Oxdolllloddxxxxxxdolccccccllooodddd
// .    .....';:cldxkO0000Okxol:;,''',,;::cccc:;,,'.......'',;:cldxxkkxxdolc:;;,'.......';coxOKXNWWWNXKOkxddddxxkkkkkkxdoollllooddxxxxkkk
//       ....',;:codxkO000OOxdoc:;,''',,,;;;;,''.......',,;:clodkO00000Okxolc::;,,''..',;:ldxOKXNWWWNNK0OkkkkkkkkkkkxxddooooodxxkOOOOO000
//       ....',;;clodxkkOOOkkdolc:;,,,,,,,,'..........,;:clodxkO0KKXKK0Okxdolcc::;;,,,;;:codkO0XXNNNNXKK0OOOOOkkkkxxdoollloodxkO0KKKXXXXX
//
// VERSION: 1.1.1
// https://github.com/Auburn/FastNoiseLite

// Port based off the C version using Odin version dev-2024-10

package fast_noise_lite
import "core:math"

// Switch between using floats or doubles for input position
FNL_USE_F64 :: #config(USE_F64, false)

when FNL_USE_F64 {
    FNL_Float :: f64
} else {
    FNL_Float :: f32
}

// Enums
Noise_Type :: enum u8 {
    Open_Simplex_2,
    Open_Simplex_2S,
    Cellular,
    Perlin,
    Value_Cubic,
    Value,
}

Rotation_Type_3d :: enum u8 {
    None,
    Improve_XY_Planes,
    Improve_XZ_Planes,
}

Fractal_Type :: enum u8 {
    None,
    FBM,
    Ridged,
    Ping_Pong,
    Domain_Warp_Progressive,
    Domain_Warp_Independent,
}

Cellular_Distance_Func :: enum u8 {
    Euclidean,
    Euclidean_SQ,
    Manhattan,
    Hybrid,
}

Cellular_Return_Type :: enum u8 {
    Cellvalue,
    Distance,
    Distance2,
    Distance2_Add,
    Distance2_Sub,
    Distance2_Mul,
    Distance2_Div,
}

Domain_Warp_Type :: enum u8 {
    Open_Simplex_2,
    Open_Simplex_2_Reduced,
    Basic_Grid,
}

/**
 * Structure containing entire noise system state.
 * @note Must only be created using create_state(optional: seed). To ensure defaults are set.
 */
FNL_State :: struct {
    /**
    * Seed used for all noise types.
    * @remark Default: 1337
    */
    seed: i32,

    /**
    * The frequency for all noise types.
    * @remark Default: 0.01
    */
    frequency: f32,

    /**
    * The noise algorithm to be used by GetNoise(...).
    * @remark Default: Open_Simplex_2
    */
    noise_type: Noise_Type,

    /**
    * Sets noise rotation type for 3D.
    * @remark Default: None
    */
    rotation_type_3d: Rotation_Type_3d,

    /**
    * The method used for combining octaves for all fractal noise types.
    * @remark Default: None
    * @remark FNL_FRACTAL_DOMAIN_WARP_... only effects fnlDomainWarp...
    */
    fractal_type: Fractal_Type,

    /**
    * The octave count for all fractal noise types.
    * @remark Default: 3
    */
    octaves: i32,

    /**
    * The octave lacunarity for all fractal noise types.
    * @remark Default: 2.0
    */
    lacunarity: f32,

    /**
    * The octave gain for all fractal noise types.
    * @remark Default: 0.5
    */
    gain: f32,

    /**
    * The octave weighting for all none Domaain Warp fractal types.
    * @remark Default: 0.0
    * @remark 
    */
    weighted_strength: f32,

    /**
    * The strength of the fractal ping pong effect.
    * @remark Default: 2.0
    */
    ping_pong_strength: f32,

    /**
    * The distance function used in cellular noise calculations.
    * @remark Default: Euclidean_SQ
    */
    cellular_distance_func: Cellular_Distance_Func,

    /**
    * The cellular return type from cellular noise calculations.
    * @remark Default: Distance
    */
    cellular_return_type: Cellular_Return_Type,

    /**
    * The maximum distance a cellular poi32 can move from it's grid position.
    * @remark Default: 1.0
    * @note Setting this higher than 1 will cause artifacts.
    */
    cellular_jitter_mod: f32,

    /**
    * The warp algorithm when using fnlDomainWarp...
    * @remark Default: OpenSimplex2
    */
    domain_warp_type: Domain_Warp_Type,

    /**
    * The maximum warp distance from original position when using fnlDomainWarp...
    * @remark Default: 1.0
    */
    domain_warp_amp: f32,
}

//constants
@private
GRADIENTS_2D := [256]f64 {
    0.130526192220052, 0.99144486137381, 0.38268343236509, 0.923879532511287, 0.608761429008721, 0.793353340291235, 0.793353340291235, 0.608761429008721,
    0.923879532511287, 0.38268343236509, 0.99144486137381, 0.130526192220051, 0.99144486137381, -0.130526192220051, 0.923879532511287, -0.38268343236509,
    0.793353340291235, -0.60876142900872, 0.608761429008721, -0.793353340291235, 0.38268343236509, -0.923879532511287, 0.130526192220052, -0.99144486137381,
    -0.130526192220052, -0.99144486137381, -0.38268343236509, -0.923879532511287, -0.608761429008721, -0.793353340291235, -0.793353340291235, -0.608761429008721,
    -0.923879532511287, -0.38268343236509, -0.99144486137381, -0.130526192220052, -0.99144486137381, 0.130526192220051, -0.923879532511287, 0.38268343236509,
    -0.793353340291235, 0.608761429008721, -0.608761429008721, 0.793353340291235, -0.38268343236509, 0.923879532511287, -0.130526192220052, 0.99144486137381,
    0.130526192220052, 0.99144486137381, 0.38268343236509, 0.923879532511287, 0.608761429008721, 0.793353340291235, 0.793353340291235, 0.608761429008721,
    0.923879532511287, 0.38268343236509, 0.99144486137381, 0.130526192220051, 0.99144486137381, -0.130526192220051, 0.923879532511287, -0.38268343236509,
    0.793353340291235, -0.60876142900872, 0.608761429008721, -0.793353340291235, 0.38268343236509, -0.923879532511287, 0.130526192220052, -0.99144486137381,
    -0.130526192220052, -0.99144486137381, -0.38268343236509, -0.923879532511287, -0.608761429008721, -0.793353340291235, -0.793353340291235, -0.608761429008721,
    -0.923879532511287, -0.38268343236509, -0.99144486137381, -0.130526192220052, -0.99144486137381, 0.130526192220051, -0.923879532511287, 0.38268343236509,
    -0.793353340291235, 0.608761429008721, -0.608761429008721, 0.793353340291235, -0.38268343236509, 0.923879532511287, -0.130526192220052, 0.99144486137381,
    0.130526192220052, 0.99144486137381, 0.38268343236509, 0.923879532511287, 0.608761429008721, 0.793353340291235, 0.793353340291235, 0.608761429008721,
    0.923879532511287, 0.38268343236509, 0.99144486137381, 0.130526192220051, 0.99144486137381, -0.130526192220051, 0.923879532511287, -0.38268343236509,
    0.793353340291235, -0.60876142900872, 0.608761429008721, -0.793353340291235, 0.38268343236509, -0.923879532511287, 0.130526192220052, -0.99144486137381,
    -0.130526192220052, -0.99144486137381, -0.38268343236509, -0.923879532511287, -0.608761429008721, -0.793353340291235, -0.793353340291235, -0.608761429008721,
    -0.923879532511287, -0.38268343236509, -0.99144486137381, -0.130526192220052, -0.99144486137381, 0.130526192220051, -0.923879532511287, 0.38268343236509,
    -0.793353340291235, 0.608761429008721, -0.608761429008721, 0.793353340291235, -0.38268343236509, 0.923879532511287, -0.130526192220052, 0.99144486137381,
    0.130526192220052, 0.99144486137381, 0.38268343236509, 0.923879532511287, 0.608761429008721, 0.793353340291235, 0.793353340291235, 0.608761429008721,
    0.923879532511287, 0.38268343236509, 0.99144486137381, 0.130526192220051, 0.99144486137381, -0.130526192220051, 0.923879532511287, -0.38268343236509,
    0.793353340291235, -0.60876142900872, 0.608761429008721, -0.793353340291235, 0.38268343236509, -0.923879532511287, 0.130526192220052, -0.99144486137381,
    -0.130526192220052, -0.99144486137381, -0.38268343236509, -0.923879532511287, -0.608761429008721, -0.793353340291235, -0.793353340291235, -0.608761429008721,
    -0.923879532511287, -0.38268343236509, -0.99144486137381, -0.130526192220052, -0.99144486137381, 0.130526192220051, -0.923879532511287, 0.38268343236509,
    -0.793353340291235, 0.608761429008721, -0.608761429008721, 0.793353340291235, -0.38268343236509, 0.923879532511287, -0.130526192220052, 0.99144486137381,
    0.130526192220052, 0.99144486137381, 0.38268343236509, 0.923879532511287, 0.608761429008721, 0.793353340291235, 0.793353340291235, 0.608761429008721,
    0.923879532511287, 0.38268343236509, 0.99144486137381, 0.130526192220051, 0.99144486137381, -0.130526192220051, 0.923879532511287, -0.38268343236509,
    0.793353340291235, -0.60876142900872, 0.608761429008721, -0.793353340291235, 0.38268343236509, -0.923879532511287, 0.130526192220052, -0.99144486137381,
    -0.130526192220052, -0.99144486137381, -0.38268343236509, -0.923879532511287, -0.608761429008721, -0.793353340291235, -0.793353340291235, -0.608761429008721,
    -0.923879532511287, -0.38268343236509, -0.99144486137381, -0.130526192220052, -0.99144486137381, 0.130526192220051, -0.923879532511287, 0.38268343236509,
    -0.793353340291235, 0.608761429008721, -0.608761429008721, 0.793353340291235, -0.38268343236509, 0.923879532511287, -0.130526192220052, 0.99144486137381,
    0.38268343236509, 0.923879532511287, 0.923879532511287, 0.38268343236509, 0.923879532511287, -0.38268343236509, 0.38268343236509, -0.923879532511287,
    -0.38268343236509, -0.923879532511287, -0.923879532511287, -0.38268343236509, -0.923879532511287, 0.38268343236509, -0.38268343236509, 0.923879532511287,
}

@private
RAND_VECS_2D := [512]f64 {
    -0.2700222198, -0.9628540911, 0.3863092627, -0.9223693152, 0.04444859006, -0.999011673, -0.5992523158, -0.8005602176, -0.7819280288, 0.6233687174, 0.9464672271, 0.3227999196, -0.6514146797, -0.7587218957, 0.9378472289, 0.347048376,
    -0.8497875957, -0.5271252623, -0.879042592, 0.4767432447, -0.892300288, -0.4514423508, -0.379844434, -0.9250503802, -0.9951650832, 0.0982163789, 0.7724397808, -0.6350880136, 0.7573283322, -0.6530343002, -0.9928004525, -0.119780055,
    -0.0532665713, 0.9985803285, 0.9754253726, -0.2203300762, -0.7665018163, 0.6422421394, 0.991636706, 0.1290606184, -0.994696838, 0.1028503788, -0.5379205513, -0.84299554, 0.5022815471, -0.8647041387, 0.4559821461, -0.8899889226,
    -0.8659131224, -0.5001944266, 0.0879458407, -0.9961252577, -0.5051684983, 0.8630207346, 0.7753185226, -0.6315704146, -0.6921944612, 0.7217110418, -0.5191659449, -0.8546734591, 0.8978622882, -0.4402764035, -0.1706774107, 0.9853269617,
    -0.9353430106, -0.3537420705, -0.9992404798, 0.03896746794, -0.2882064021, -0.9575683108, -0.9663811329, 0.2571137995, -0.8759714238, -0.4823630009, -0.8303123018, -0.5572983775, 0.05110133755, -0.9986934731, -0.8558373281, -0.5172450752,
    0.09887025282, 0.9951003332, 0.9189016087, 0.3944867976, -0.2439375892, -0.9697909324, -0.8121409387, -0.5834613061, -0.9910431363, 0.1335421355, 0.8492423985, -0.5280031709, -0.9717838994, -0.2358729591, 0.9949457207, 0.1004142068,
    0.6241065508, -0.7813392434, 0.662910307, 0.7486988212, -0.7197418176, 0.6942418282, -0.8143370775, -0.5803922158, 0.104521054, -0.9945226741, -0.1065926113, -0.9943027784, 0.445799684, -0.8951327509, 0.105547406, 0.9944142724,
    -0.992790267, 0.1198644477, -0.8334366408, 0.552615025, 0.9115561563, -0.4111755999, 0.8285544909, -0.5599084351, 0.7217097654, -0.6921957921, 0.4940492677, -0.8694339084, -0.3652321272, -0.9309164803, -0.9696606758, 0.2444548501,
    0.08925509731, -0.996008799, 0.5354071276, -0.8445941083, -0.1053576186, 0.9944343981, -0.9890284586, 0.1477251101, 0.004856104961, 0.9999882091, 0.9885598478, 0.1508291331, 0.9286129562, -0.3710498316, -0.5832393863, -0.8123003252,
    0.3015207509, 0.9534596146, -0.9575110528, 0.2883965738, 0.9715802154, -0.2367105511, 0.229981792, 0.9731949318, 0.955763816, -0.2941352207, 0.740956116, 0.6715534485, -0.9971513787, -0.07542630764, 0.6905710663, -0.7232645452,
    -0.290713703, -0.9568100872, 0.5912777791, -0.8064679708, -0.9454592212, -0.325740481, 0.6664455681, 0.74555369, 0.6236134912, 0.7817328275, 0.9126993851, -0.4086316587, -0.8191762011, 0.5735419353, -0.8812745759, -0.4726046147,
    0.9953313627, 0.09651672651, 0.9855650846, -0.1692969699, -0.8495980887, 0.5274306472, 0.6174853946, -0.7865823463, 0.8508156371, 0.52546432, 0.9985032451, -0.05469249926, 0.1971371563, -0.9803759185, 0.6607855748, -0.7505747292,
    -0.03097494063, 0.9995201614, -0.6731660801, 0.739491331, -0.7195018362, -0.6944905383, 0.9727511689, 0.2318515979, 0.9997059088, -0.0242506907, 0.4421787429, -0.8969269532, 0.9981350961, -0.061043673, -0.9173660799, -0.3980445648,
    -0.8150056635, -0.5794529907, -0.8789331304, 0.4769450202, 0.0158605829, 0.999874213, -0.8095464474, 0.5870558317, -0.9165898907, -0.3998286786, -0.8023542565, 0.5968480938, -0.5176737917, 0.8555780767, -0.8154407307, -0.5788405779,
    0.4022010347, -0.9155513791, -0.9052556868, -0.4248672045, 0.7317445619, 0.6815789728, -0.5647632201, -0.8252529947, -0.8403276335, -0.5420788397, -0.9314281527, 0.363925262, 0.5238198472, 0.8518290719, 0.7432803869, -0.6689800195,
    -0.985371561, -0.1704197369, 0.4601468731, 0.88784281, 0.825855404, 0.5638819483, 0.6182366099, 0.7859920446, 0.8331502863, -0.553046653, 0.1500307506, 0.9886813308, -0.662330369, -0.7492119075, -0.668598664, 0.743623444,
    0.7025606278, 0.7116238924, -0.5419389763, -0.8404178401, -0.3388616456, 0.9408362159, 0.8331530315, 0.5530425174, -0.2989720662, -0.9542618632, 0.2638522993, 0.9645630949, 0.124108739, -0.9922686234, -0.7282649308, -0.6852956957,
    0.6962500149, 0.7177993569, -0.9183535368, 0.3957610156, -0.6326102274, -0.7744703352, -0.9331891859, -0.359385508, -0.1153779357, -0.9933216659, 0.9514974788, -0.3076565421, -0.08987977445, -0.9959526224, 0.6678496916, 0.7442961705,
    0.7952400393, -0.6062947138, -0.6462007402, -0.7631674805, -0.2733598753, 0.9619118351, 0.9669590226, -0.254931851, -0.9792894595, 0.2024651934, -0.5369502995, -0.8436138784, -0.270036471, -0.9628500944, -0.6400277131, 0.7683518247,
    -0.7854537493, -0.6189203566, 0.06005905383, -0.9981948257, -0.02455770378, 0.9996984141, -0.65983623, 0.751409442, -0.6253894466, -0.7803127835, -0.6210408851, -0.7837781695, 0.8348888491, 0.5504185768, -0.1592275245, 0.9872419133,
    0.8367622488, 0.5475663786, -0.8675753916, -0.4973056806, -0.2022662628, -0.9793305667, 0.9399189937, 0.3413975472, 0.9877404807, -0.1561049093, -0.9034455656, 0.4287028224, 0.1269804218, -0.9919052235, -0.3819600854, 0.924178821,
    0.9754625894, 0.2201652486, -0.3204015856, -0.9472818081, -0.9874760884, 0.1577687387, 0.02535348474, -0.9996785487, 0.4835130794, -0.8753371362, -0.2850799925, -0.9585037287, -0.06805516006, -0.99768156, -0.7885244045, -0.6150034663,
    0.3185392127, -0.9479096845, 0.8880043089, 0.4598351306, 0.6476921488, -0.7619021462, 0.9820241299, 0.1887554194, 0.9357275128, -0.3527237187, -0.8894895414, 0.4569555293, 0.7922791302, 0.6101588153, 0.7483818261, 0.6632681526,
    -0.7288929755, -0.6846276581, 0.8729032783, -0.4878932944, 0.8288345784, 0.5594937369, 0.08074567077, 0.9967347374, 0.9799148216, -0.1994165048, -0.580730673, -0.8140957471, -0.4700049791, -0.8826637636, 0.2409492979, 0.9705377045,
    0.9437816757, -0.3305694308, -0.8927998638, -0.4504535528, -0.8069622304, 0.5906030467, 0.06258973166, 0.9980393407, -0.9312597469, 0.3643559849, 0.5777449785, 0.8162173362, -0.3360095855, -0.941858566, 0.697932075, -0.7161639607,
    -0.002008157227, -0.9999979837, -0.1827294312, -0.9831632392, -0.6523911722, 0.7578824173, -0.4302626911, -0.9027037258, -0.9985126289, -0.05452091251, -0.01028102172, -0.9999471489, -0.4946071129, 0.8691166802, -0.2999350194, 0.9539596344,
    0.8165471961, 0.5772786819, 0.2697460475, 0.962931498, -0.7306287391, -0.6827749597, -0.7590952064, -0.6509796216, -0.907053853, 0.4210146171, -0.5104861064, -0.8598860013, 0.8613350597, 0.5080373165, 0.5007881595, -0.8655698812,
    -0.654158152, 0.7563577938, -0.8382755311, -0.545246856, 0.6940070834, 0.7199681717, 0.06950936031, 0.9975812994, 0.1702942185, -0.9853932612, 0.2695973274, 0.9629731466, 0.5519612192, -0.8338697815, 0.225657487, -0.9742067022,
    0.4215262855, -0.9068161835, 0.4881873305, -0.8727388672, -0.3683854996, -0.9296731273, -0.9825390578, 0.1860564427, 0.81256471, 0.5828709909, 0.3196460933, -0.9475370046, 0.9570913859, 0.2897862643, -0.6876655497, -0.7260276109,
    -0.9988770922, -0.047376731, -0.1250179027, 0.992154486, -0.8280133617, 0.560708367, 0.9324863769, -0.3612051451, 0.6394653183, 0.7688199442, -0.01623847064, -0.9998681473, -0.9955014666, -0.09474613458, -0.81453315, 0.580117012,
    0.4037327978, -0.9148769469, 0.9944263371, 0.1054336766, -0.1624711654, 0.9867132919, -0.9949487814, -0.100383875, -0.6995302564, 0.7146029809, 0.5263414922, -0.85027327, -0.5395221479, 0.841971408, 0.6579370318, 0.7530729462,
    0.01426758847, -0.9998982128, -0.6734383991, 0.7392433447, 0.639412098, -0.7688642071, 0.9211571421, 0.3891908523, -0.146637214, -0.9891903394, -0.782318098, 0.6228791163, -0.5039610839, -0.8637263605, -0.7743120191, -0.6328039957,
}

@private
GRADIENTS_3D := [256]f32 {
    0, 1, 1, 0,  0,-1, 1, 0,  0, 1,-1, 0,  0,-1,-1, 0,
    1, 0, 1, 0, -1, 0, 1, 0,  1, 0,-1, 0, -1, 0,-1, 0,
    1, 1, 0, 0, -1, 1, 0, 0,  1,-1, 0, 0, -1,-1, 0, 0,
    0, 1, 1, 0,  0,-1, 1, 0,  0, 1,-1, 0,  0,-1,-1, 0,
    1, 0, 1, 0, -1, 0, 1, 0,  1, 0,-1, 0, -1, 0,-1, 0,
    1, 1, 0, 0, -1, 1, 0, 0,  1,-1, 0, 0, -1,-1, 0, 0,
    0, 1, 1, 0,  0,-1, 1, 0,  0, 1,-1, 0,  0,-1,-1, 0,
    1, 0, 1, 0, -1, 0, 1, 0,  1, 0,-1, 0, -1, 0,-1, 0,
    1, 1, 0, 0, -1, 1, 0, 0,  1,-1, 0, 0, -1,-1, 0, 0,
    0, 1, 1, 0,  0,-1, 1, 0,  0, 1,-1, 0,  0,-1,-1, 0,
    1, 0, 1, 0, -1, 0, 1, 0,  1, 0,-1, 0, -1, 0,-1, 0,
    1, 1, 0, 0, -1, 1, 0, 0,  1,-1, 0, 0, -1,-1, 0, 0,
    0, 1, 1, 0,  0,-1, 1, 0,  0, 1,-1, 0,  0,-1,-1, 0,
    1, 0, 1, 0, -1, 0, 1, 0,  1, 0,-1, 0, -1, 0,-1, 0,
    1, 1, 0, 0, -1, 1, 0, 0,  1,-1, 0, 0, -1,-1, 0, 0,
    1, 1, 0, 0,  0,-1, 1, 0, -1, 1, 0, 0,  0,-1,-1, 0,
}

@private
RAND_VECS_3D := [1024]f64 {
    -0.7292736885, -0.6618439697, 0.1735581948, 0, 0.790292081, -0.5480887466, -0.2739291014, 0, 0.7217578935, 0.6226212466, -0.3023380997, 0, 0.565683137, -0.8208298145, -0.0790000257, 0, 0.760049034, -0.5555979497, -0.3370999617, 0, 0.3713945616, 0.5011264475, 0.7816254623, 0, -0.1277062463, -0.4254438999, -0.8959289049, 0, -0.2881560924, -0.5815838982, 0.7607405838, 0,
    0.5849561111, -0.662820239, -0.4674352136, 0, 0.3307171178, 0.0391653737, 0.94291689, 0, 0.8712121778, -0.4113374369, -0.2679381538, 0, 0.580981015, 0.7021915846, 0.4115677815, 0, 0.503756873, 0.6330056931, -0.5878203852, 0, 0.4493712205, 0.601390195, 0.6606022552, 0, -0.6878403724, 0.09018890807, -0.7202371714, 0, -0.5958956522, -0.6469350577, 0.475797649, 0,
    -0.5127052122, 0.1946921978, -0.8361987284, 0, -0.9911507142, -0.05410276466, -0.1212153153, 0, -0.2149721042, 0.9720882117, -0.09397607749, 0, -0.7518650936, -0.5428057603, 0.3742469607, 0, 0.5237068895, 0.8516377189, -0.02107817834, 0, 0.6333504779, 0.1926167129, -0.7495104896, 0, -0.06788241606, 0.3998305789, 0.9140719259, 0, -0.5538628599, -0.4729896695, -0.6852128902, 0,
    -0.7261455366, -0.5911990757, 0.3509933228, 0, -0.9229274737, -0.1782808786, 0.3412049336, 0, -0.6968815002, 0.6511274338, 0.3006480328, 0, 0.9608044783, -0.2098363234, -0.1811724921, 0, 0.06817146062, -0.9743405129, 0.2145069156, 0, -0.3577285196, -0.6697087264, -0.6507845481, 0, -0.1868621131, 0.7648617052, -0.6164974636, 0, -0.6541697588, 0.3967914832, 0.6439087246, 0,
    0.6993340405, -0.6164538506, 0.3618239211, 0, -0.1546665739, 0.6291283928, 0.7617583057, 0, -0.6841612949, -0.2580482182, -0.6821542638, 0, 0.5383980957, 0.4258654885, 0.7271630328, 0, -0.5026987823, -0.7939832935, -0.3418836993, 0, 0.3202971715, 0.2834415347, 0.9039195862, 0, 0.8683227101, -0.0003762656404, -0.4959995258, 0, 0.791120031, -0.08511045745, 0.6057105799, 0,
    -0.04011016052, -0.4397248749, 0.8972364289, 0, 0.9145119872, 0.3579346169, -0.1885487608, 0, -0.9612039066, -0.2756484276, 0.01024666929, 0, 0.6510361721, -0.2877799159, -0.7023778346, 0, -0.2041786351, 0.7365237271, 0.644859585, 0, -0.7718263711, 0.3790626912, 0.5104855816, 0, -0.3060082741, -0.7692987727, 0.5608371729, 0, 0.454007341, -0.5024843065, 0.7357899537, 0,
    0.4816795475, 0.6021208291, -0.6367380315, 0, 0.6961980369, -0.3222197429, 0.641469197, 0, -0.6532160499, -0.6781148932, 0.3368515753, 0, 0.5089301236, -0.6154662304, -0.6018234363, 0, -0.1635919754, -0.9133604627, -0.372840892, 0, 0.52408019, -0.8437664109, 0.1157505864, 0, 0.5902587356, 0.4983817807, -0.6349883666, 0, 0.5863227872, 0.494764745, 0.6414307729, 0,
    0.6779335087, 0.2341345225, 0.6968408593, 0, 0.7177054546, -0.6858979348, 0.120178631, 0, -0.5328819713, -0.5205125012, 0.6671608058, 0, -0.8654874251, -0.0700727088, -0.4960053754, 0, -0.2861810166, 0.7952089234, 0.5345495242, 0, -0.04849529634, 0.9810836427, -0.1874115585, 0, -0.6358521667, 0.6058348682, 0.4781800233, 0, 0.6254794696, -0.2861619734, 0.7258696564, 0,
    -0.2585259868, 0.5061949264, -0.8227581726, 0, 0.02136306781, 0.5064016808, -0.8620330371, 0, 0.200111773, 0.8599263484, 0.4695550591, 0, 0.4743561372, 0.6014985084, -0.6427953014, 0, 0.6622993731, -0.5202474575, -0.5391679918, 0, 0.08084972818, -0.6532720452, 0.7527940996, 0, -0.6893687501, 0.0592860349, 0.7219805347, 0, -0.1121887082, -0.9673185067, 0.2273952515, 0,
    0.7344116094, 0.5979668656, -0.3210532909, 0, 0.5789393465, -0.2488849713, 0.7764570201, 0, 0.6988182827, 0.3557169806, -0.6205791146, 0, -0.8636845529, -0.2748771249, -0.4224826141, 0, -0.4247027957, -0.4640880967, 0.777335046, 0, 0.5257722489, -0.8427017621, 0.1158329937, 0, 0.9343830603, 0.316302472, -0.1639543925, 0, -0.1016836419, -0.8057303073, -0.5834887393, 0,
    -0.6529238969, 0.50602126, -0.5635892736, 0, -0.2465286165, -0.9668205684, -0.06694497494, 0, -0.9776897119, -0.2099250524, -0.007368825344, 0, 0.7736893337, 0.5734244712, 0.2694238123, 0, -0.6095087895, 0.4995678998, 0.6155736747, 0, 0.5794535482, 0.7434546771, 0.3339292269, 0, -0.8226211154, 0.08142581855, 0.5627293636, 0, -0.510385483, 0.4703667658, 0.7199039967, 0,
    -0.5764971849, -0.07231656274, -0.8138926898, 0, 0.7250628871, 0.3949971505, -0.5641463116, 0, -0.1525424005, 0.4860840828, -0.8604958341, 0, -0.5550976208, -0.4957820792, 0.667882296, 0, -0.1883614327, 0.9145869398, 0.357841725, 0, 0.7625556724, -0.5414408243, -0.3540489801, 0, -0.5870231946, -0.3226498013, -0.7424963803, 0, 0.3051124198, 0.2262544068, -0.9250488391, 0,
    0.6379576059, 0.577242424, -0.5097070502, 0, -0.5966775796, 0.1454852398, -0.7891830656, 0, -0.658330573, 0.6555487542, -0.3699414651, 0, 0.7434892426, 0.2351084581, 0.6260573129, 0, 0.5562114096, 0.8264360377, -0.0873632843, 0, -0.3028940016, -0.8251527185, 0.4768419182, 0, 0.1129343818, -0.985888439, -0.1235710781, 0, 0.5937652891, -0.5896813806, 0.5474656618, 0,
    0.6757964092, -0.5835758614, -0.4502648413, 0, 0.7242302609, -0.1152719764, 0.6798550586, 0, -0.9511914166, 0.0753623979, -0.2992580792, 0, 0.2539470961, -0.1886339355, 0.9486454084, 0, 0.571433621, -0.1679450851, -0.8032795685, 0, -0.06778234979, 0.3978269256, 0.9149531629, 0, 0.6074972649, 0.733060024, -0.3058922593, 0, -0.5435478392, 0.1675822484, 0.8224791405, 0,
    -0.5876678086, -0.3380045064, -0.7351186982, 0, -0.7967562402, 0.04097822706, -0.6029098428, 0, -0.1996350917, 0.8706294745, 0.4496111079, 0, -0.02787660336, -0.9106232682, -0.4122962022, 0, -0.7797625996, -0.6257634692, 0.01975775581, 0, -0.5211232846, 0.7401644346, -0.4249554471, 0, 0.8575424857, 0.4053272873, -0.3167501783, 0, 0.1045223322, 0.8390195772, -0.5339674439, 0,
    0.3501822831, 0.9242524096, -0.1520850155, 0, 0.1987849858, 0.07647613266, 0.9770547224, 0, 0.7845996363, 0.6066256811, -0.1280964233, 0, 0.09006737436, -0.9750989929, -0.2026569073, 0, -0.8274343547, -0.542299559, 0.1458203587, 0, -0.3485797732, -0.415802277, 0.840000362, 0, -0.2471778936, -0.7304819962, -0.6366310879, 0, -0.3700154943, 0.8577948156, 0.3567584454, 0,
    0.5913394901, -0.548311967, -0.5913303597, 0, 0.1204873514, -0.7626472379, -0.6354935001, 0, 0.616959265, 0.03079647928, 0.7863922953, 0, 0.1258156836, -0.6640829889, -0.7369967419, 0, -0.6477565124, -0.1740147258, -0.7417077429, 0, 0.6217889313, -0.7804430448, -0.06547655076, 0, 0.6589943422, -0.6096987708, 0.4404473475, 0, -0.2689837504, -0.6732403169, -0.6887635427, 0,
    -0.3849775103, 0.5676542638, 0.7277093879, 0, 0.5754444408, 0.8110471154, -0.1051963504, 0, 0.9141593684, 0.3832947817, 0.131900567, 0, -0.107925319, 0.9245493968, 0.3654593525, 0, 0.377977089, 0.3043148782, 0.8743716458, 0, -0.2142885215, -0.8259286236, 0.5214617324, 0, 0.5802544474, 0.4148098596, -0.7008834116, 0, -0.1982660881, 0.8567161266, -0.4761596756, 0,
    -0.03381553704, 0.3773180787, -0.9254661404, 0, -0.6867922841, -0.6656597827, 0.2919133642, 0, 0.7731742607, -0.2875793547, -0.5652430251, 0, -0.09655941928, 0.9193708367, -0.3813575004, 0, 0.2715702457, -0.9577909544, -0.09426605581, 0, 0.2451015704, -0.6917998565, -0.6792188003, 0, 0.977700782, -0.1753855374, 0.1155036542, 0, -0.5224739938, 0.8521606816, 0.02903615945, 0,
    -0.7734880599, -0.5261292347, 0.3534179531, 0, -0.7134492443, -0.269547243, 0.6467878011, 0, 0.1644037271, 0.5105846203, -0.8439637196, 0, 0.6494635788, 0.05585611296, 0.7583384168, 0, -0.4711970882, 0.5017280509, -0.7254255765, 0, -0.6335764307, -0.2381686273, -0.7361091029, 0, -0.9021533097, -0.270947803, -0.3357181763, 0, -0.3793711033, 0.872258117, 0.3086152025, 0,
    -0.6855598966, -0.3250143309, 0.6514394162, 0, 0.2900942212, -0.7799057743, -0.5546100667, 0, -0.2098319339, 0.85037073, 0.4825351604, 0, -0.4592603758, 0.6598504336, -0.5947077538, 0, 0.8715945488, 0.09616365406, -0.4807031248, 0, -0.6776666319, 0.7118504878, -0.1844907016, 0, 0.7044377633, 0.312427597, 0.637304036, 0, -0.7052318886, -0.2401093292, -0.6670798253, 0,
    0.081921007, -0.7207336136, -0.6883545647, 0, -0.6993680906, -0.5875763221, -0.4069869034, 0, -0.1281454481, 0.6419895885, 0.7559286424, 0, -0.6337388239, -0.6785471501, -0.3714146849, 0, 0.5565051903, -0.2168887573, -0.8020356851, 0, -0.5791554484, 0.7244372011, -0.3738578718, 0, 0.1175779076, -0.7096451073, 0.6946792478, 0, -0.6134619607, 0.1323631078, 0.7785527795, 0,
    0.6984635305, -0.02980516237, -0.715024719, 0, 0.8318082963, -0.3930171956, 0.3919597455, 0, 0.1469576422, 0.05541651717, -0.9875892167, 0, 0.708868575, -0.2690503865, 0.6520101478, 0, 0.2726053183, 0.67369766, -0.68688995, 0, -0.6591295371, 0.3035458599, -0.6880466294, 0, 0.4815131379, -0.7528270071, 0.4487723203, 0, 0.9430009463, 0.1675647412, -0.2875261255, 0,
    0.434802957, 0.7695304522, -0.4677277752, 0, 0.3931996188, 0.594473625, 0.7014236729, 0, 0.7254336655, -0.603925654, 0.3301814672, 0, 0.7590235227, -0.6506083235, 0.02433313207, 0, -0.8552768592, -0.3430042733, 0.3883935666, 0, -0.6139746835, 0.6981725247, 0.3682257648, 0, -0.7465905486, -0.5752009504, 0.3342849376, 0, 0.5730065677, 0.810555537, -0.1210916791, 0,
    -0.9225877367, -0.3475211012, -0.167514036, 0, -0.7105816789, -0.4719692027, -0.5218416899, 0, -0.08564609717, 0.3583001386, 0.929669703, 0, -0.8279697606, -0.2043157126, 0.5222271202, 0, 0.427944023, 0.278165994, 0.8599346446, 0, 0.5399079671, -0.7857120652, -0.3019204161, 0, 0.5678404253, -0.5495413974, -0.6128307303, 0, -0.9896071041, 0.1365639107, -0.04503418428, 0,
    -0.6154342638, -0.6440875597, 0.4543037336, 0, 0.1074204368, -0.7946340692, 0.5975094525, 0, -0.3595449969, -0.8885529948, 0.28495784, 0, -0.2180405296, 0.1529888965, 0.9638738118, 0, -0.7277432317, -0.6164050508, -0.3007234646, 0, 0.7249729114, -0.00669719484, 0.6887448187, 0, -0.5553659455, -0.5336586252, 0.6377908264, 0, 0.5137558015, 0.7976208196, -0.3160000073, 0,
    -0.3794024848, 0.9245608561, -0.03522751494, 0, 0.8229248658, 0.2745365933, -0.4974176556, 0, -0.5404114394, 0.6091141441, 0.5804613989, 0, 0.8036581901, -0.2703029469, 0.5301601931, 0, 0.6044318879, 0.6832968393, 0.4095943388, 0, 0.06389988817, 0.9658208605, -0.2512108074, 0, 0.1087113286, 0.7402471173, -0.6634877936, 0, -0.713427712, -0.6926784018, 0.1059128479, 0,
    0.6458897819, -0.5724548511, -0.5050958653, 0, -0.6553931414, 0.7381471625, 0.159995615, 0, 0.3910961323, 0.9188871375, -0.05186755998, 0, -0.4879022471, -0.5904376907, 0.6429111375, 0, 0.6014790094, 0.7707441366, -0.2101820095, 0, -0.5677173047, 0.7511360995, 0.3368851762, 0, 0.7858573506, 0.226674665, 0.5753666838, 0, -0.4520345543, -0.604222686, -0.6561857263, 0,
    0.002272116345, 0.4132844051, -0.9105991643, 0, -0.5815751419, -0.5162925989, 0.6286591339, 0, -0.03703704785, 0.8273785755, 0.5604221175, 0, -0.5119692504, 0.7953543429, -0.3244980058, 0, -0.2682417366, -0.9572290247, -0.1084387619, 0, -0.2322482736, -0.9679131102, -0.09594243324, 0, 0.3554328906, -0.8881505545, 0.2913006227, 0, 0.7346520519, -0.4371373164, 0.5188422971, 0,
    0.9985120116, 0.04659011161, -0.02833944577, 0, -0.3727687496, -0.9082481361, 0.1900757285, 0, 0.91737377, -0.3483642108, 0.1925298489, 0, 0.2714911074, 0.4147529736, -0.8684886582, 0, 0.5131763485, -0.7116334161, 0.4798207128, 0, -0.8737353606, 0.18886992, -0.4482350644, 0, 0.8460043821, -0.3725217914, 0.3814499973, 0, 0.8978727456, -0.1780209141, -0.4026575304, 0,
    0.2178065647, -0.9698322841, -0.1094789531, 0, -0.1518031304, -0.7788918132, -0.6085091231, 0, -0.2600384876, -0.4755398075, -0.8403819825, 0, 0.572313509, -0.7474340931, -0.3373418503, 0, -0.7174141009, 0.1699017182, -0.6756111411, 0, -0.684180784, 0.02145707593, -0.7289967412, 0, -0.2007447902, 0.06555605789, -0.9774476623, 0, -0.1148803697, -0.8044887315, 0.5827524187, 0,
    -0.7870349638, 0.03447489231, 0.6159443543, 0, -0.2015596421, 0.6859872284, 0.6991389226, 0, -0.08581082512, -0.10920836, -0.9903080513, 0, 0.5532693395, 0.7325250401, -0.396610771, 0, -0.1842489331, -0.9777375055, -0.1004076743, 0, 0.0775473789, -0.9111505856, 0.4047110257, 0, 0.1399838409, 0.7601631212, -0.6344734459, 0, 0.4484419361, -0.845289248, 0.2904925424, 0,
}

// Utilities

@private
fast_sqrt :: math.sqrt

@private
fast_floor :: #force_inline proc(f: FNL_Float) -> i32 {
    return (f >= 0 ? i32(f) : i32(f) - 1)
}

@private
fast_round :: #force_inline proc(f: FNL_Float) -> i32 {
     return (f >= 0) ? i32(f + 0.5) : i32(f - 0.5)
}

@private
lerp :: #force_inline proc(a, b, t: f32) -> f32 {
    return a + t * (b - a)
}

@private
i32erp_hermite :: #force_inline  proc(t: f32) -> f32 {
    return t * t * (3 - 2 * t)
}

@private
i32erp_qui32ic :: #force_inline proc(t: f32) -> f32 {
    return t * t * t * (t * (t * 6 - 15) + 10)
 }

@private
cubic_lerp :: #force_inline proc(a, b, c, d, t: f32) -> f32 {
    p: f32 = (d - c) - (a - b)
    return t * t * t * p + t * t * ((a - b) - p) + t * (c - a) + b
}

@private
ping_pong :: #force_inline proc (t: f32) -> f32 {
    t := t
    t -= f32(i32(t * 0.5) * 2)
    return t < 1 ? t : 2 - t
}

@private
calculate_fractal_bounding :: proc(state: FNL_State) -> f32 {
    gain: f32 = math.abs(state.gain)
    amp: f32 = gain
    ampFractal: f32 = 1.0
    for _ in 1..<state.octaves {
        ampFractal += amp
        amp *= gain
    }
    return 1.0 / ampFractal
}

// Hashing
PRIME_X: i32 =  501125321
PRIME_Y: i32 = 1136930381
PRIME_Z: i32 = 1720413743

@private
hash_2d :: #force_inline proc (seed, xPrimed, yPrimed: i32) -> i32 {
    hash := seed ~ xPrimed ~ yPrimed
    hash *= 0x27d4eb2d
    return hash
}

@private
hash_3d :: #force_inline proc(seed, xPrimed, yPrimed, zPrimed: i32) -> i32 {
    hash := seed ~ xPrimed ~ yPrimed ~ zPrimed

    hash *= 0x27d4eb2d
    return hash
}

@private
val_coord_2d :: proc(seed, xPrimed, yPrimed: i32) -> f32 {
    hash := hash_2d(seed, xPrimed, yPrimed)
    hash *= hash
    hash ~= hash << 19
    return f32(hash) * (1 / 2147483648.0)
}

@private
val_coord_3D :: proc(seed, xPrimed, yPrimed, zPrimed: i32) -> f32 {
    hash := hash_3d(seed, xPrimed, yPrimed, zPrimed)
    hash *= hash
    hash ~= hash << 19
    return f32(hash) * (1 / 2147483648.0)
}


@private
grad_coord_2d :: proc (seed, xPrimed, yPrimed: i32, xd, yd: f32) -> f32 {
    hash := hash_2d(seed, xPrimed, yPrimed)
    hash ~= hash >> 15
    hash &= 127 << 1
    return xd * f32(GRADIENTS_2D[hash]) + yd * f32(GRADIENTS_2D[hash | 1])
}

@private
grad_coord_3d :: proc (seed, xPrimed, yPrimed, zPrimed: i32, xd, yd, zd: f32) -> f32 {
    hash := hash_3d(seed, xPrimed, yPrimed, zPrimed)
    hash ~= hash >> 15
    hash &= 63 << 2
    return xd * GRADIENTS_3D[hash] + yd * GRADIENTS_3D[hash | 1] + zd * GRADIENTS_3D[hash | 2]
}

@private
grad_coord_out_2d :: proc (seed, xPrimed, yPrimed: i32, xo, yo: ^f32) {
    hash := hash_2d(seed, xPrimed, yPrimed) & (255 << 1)

    xo^ = f32(RAND_VECS_2D[hash])
    yo^ = f32(RAND_VECS_2D[hash | 1])
}

@private
grad_coord_out_3d :: proc (seed, xPrimed, yPrimed, zPrimed: i32, xo, yo, zo: ^f32) {
    hash := hash_3d(seed, xPrimed, yPrimed, zPrimed) & (255 << 2)

    xo^ = f32(RAND_VECS_3D[hash])
    yo^ = f32(RAND_VECS_3D[hash | 1])
    zo^ = f32(RAND_VECS_3D[hash | 2])
}

@private
grad_coord_dual_2d :: proc (seed, xPrimed, yPrimed: i32, xd, yd: f32, xo, yo: ^f32) {
    hash := hash_2d(seed, xPrimed, yPrimed)
    index1 := hash & (127 << 1)
    index2 := (hash >> 7) & (255 << 1)

    xg := f32(GRADIENTS_2D[index1])
    yg := f32(GRADIENTS_2D[index1 | 1])
    value := xd * xg + yd * yg

    xgo := f32(RAND_VECS_2D[index2])
    ygo := f32(RAND_VECS_2D[index2 | 1])

    xo^ = value * xgo
    yo^ = value * ygo
}

@private
grad_coord_dual_3d :: proc (seed, xPrimed, yPrimed, zPrimed: i32, xd, yd, zd: f32, xo, yo, zo: ^f32) {
    hash := hash_3d(seed, xPrimed, yPrimed, zPrimed)
    index1 := hash & (63 << 2)
    index2 := (hash >> 6) & (255 << 2)

    xg := GRADIENTS_3D[index1]
    yg := GRADIENTS_3D[index1 | 1]
    zg := GRADIENTS_3D[index1 | 2]
    value := xd * xg + yd * yg + zd * zg

    xgo := f32(RAND_VECS_3D[index2])
    ygo := f32(RAND_VECS_3D[index2 | 1])
    zgo := f32(RAND_VECS_3D[index2 | 2])

    xo^ = value * xgo
    yo^ = value * ygo
    zo^ = value * zgo
}


// Generic Noise Gen

@private
gen_noise_single_2d :: proc (state: FNL_State, seed: i32,  x, y: FNL_Float) -> f32 {
    switch (state.noise_type)
    {
    case .Open_Simplex_2:
        return single_simplex_2d(seed, x, y)
    case .Open_Simplex_2S:
        return single_open_simplex2s_2d(seed, x, y)
    case .Cellular:
        return single_cellular_2d(state, seed, x, y)
    case .Perlin:
        return single_perlin_2d(seed, x, y)
    case .Value_Cubic:
        return single_value_cubic_2d(seed, x, y)
    case .Value:
        return single_value_2d(seed, x, y)
    case:
        return 0
    }
}

@private
gen_noise_single_3d :: proc (state: FNL_State, seed: i32, x, y, z: FNL_Float) -> f32 {
    switch (state.noise_type)
    {
    case .Open_Simplex_2:
        return single_open_simplex2_3d(seed, x, y, z)
    case .Open_Simplex_2S:
        return single_open_simplex2s_3d(seed, x, y, z)
    case .Cellular:
        return single_cellular_3d(state, seed, x, y, z)
    case .Perlin:
        return single_perlin_3d(seed, x, y, z)
    case .Value_Cubic:
        return single_value_cubic_3d(seed, x, y, z)
    case .Value:
        return single_value_3d(seed, x, y, z)
    case:
        return 0
    }
}

// Noise Coordinate Transforms (frequency, and possible skew or rotation)

@private
transform_noise_coordinate_2d :: proc (state: FNL_State, x, y: ^FNL_Float) {
    x^ *= FNL_Float(state.frequency)
    y^ *= FNL_Float(state.frequency)

    #partial switch (state.noise_type)
    {
    case .Open_Simplex_2, .Open_Simplex_2S:
        SQRT3 :: FNL_Float(1.7320508075688772935274463415059)
        F2 : FNL_Float : 0.5 * (SQRT3 - 1)
        t := (x^ + y^) * F2
        x^ += t
        y^ += t
    }
}

@private
transform_noise_coordinate_3d :: proc (state: FNL_State, x, y, z: ^FNL_Float) {
    x^ *= FNL_Float(state.frequency)
    y^ *= FNL_Float(state.frequency)
    z^ *= FNL_Float(state.frequency)

    #partial switch (state.rotation_type_3d)
    {
    case .Improve_XY_Planes:
        xy :FNL_Float = x^ + y^
        s2 :FNL_Float = xy * -FNL_Float(0.211324865405187)
        z^ *= FNL_Float(0.577350269189626)
        x^ += s2 - z^
        y^ = y^ + s2 - z^
        z^ += xy * FNL_Float(0.577350269189626)
    case .Improve_XZ_Planes:
        xz :FNL_Float = x^ + z^
        s2 :FNL_Float = xz * -FNL_Float(0.211324865405187)
        y^ *= FNL_Float(0.577350269189626)
        x^ += s2 - y^
        z^ += s2 - y^
        y^ += xz * FNL_Float(0.577350269189626)
    case:
        #partial switch (state.noise_type)
        {
        case .Open_Simplex_2, .Open_Simplex_2S:
            R3 : FNL_Float : 2.0 / 3.0
            r: FNL_Float = (x^ + y^ + z^) * R3 // Rotation, not skew
            x^ = r - x^
            y^ = r - y^
            z^ = r - z^
        }
    }
}

// Domain Warp Coordinate Transforms

@private
transform_domain_warp_coordinate_2d :: proc (state: FNL_State, x, y: ^FNL_Float) {
    #partial switch (state.domain_warp_type)
    {
    case .Open_Simplex_2, .Open_Simplex_2_Reduced:
        SQRT3 :: FNL_Float(1.7320508075688772935274463415059)
        F2 : FNL_Float : 0.5 * (SQRT3 - 1)
        t: FNL_Float = (x^ + y^) * F2
        x^ += t
        y^ += t
    }
}

@private
transform_domain_warp_coordinate_3d :: proc (state: FNL_State, x, y, z: ^FNL_Float) {
    #partial switch (state.rotation_type_3d)
    {
    case .Improve_XY_Planes:
        xy := x^ + y^
        s2 := xy * -FNL_Float(0.211324865405187)
        z^ *= FNL_Float(0.577350269189626)
        x^ += s2 - z^
        y^ = y^ + s2 - z^
        z^ += xy * FNL_Float(0.577350269189626)
    case .Improve_XZ_Planes:
        xz := x^ + z^
        s2 := xz * -FNL_Float(0.211324865405187)
        y^ *= FNL_Float(0.577350269189626)
        x^ += s2 - y^
        z^ += s2 - y^
        y^ += xz * FNL_Float(0.577350269189626)
    case:
        #partial switch (state.domain_warp_type)
        {
        case .Open_Simplex_2, .Open_Simplex_2_Reduced:
            R3 : FNL_Float : FNL_Float(2.0 / 3.0)
            r: FNL_Float = (x^ + y^ + z^) * R3 // Rotation, not skew
            x^ = r - x^
            y^ = r - y^
            z^ = r - z^
        }
    }
}

// Fractal FBm
@private
gen_fractal_fbm_2d :: proc(state: FNL_State, x, y: FNL_Float) -> f32 {
    x := x; y := y
    seed := state.seed
    sum  :f32= 0.0
    amp  := calculate_fractal_bounding(state)

    for _ in 0..<state.octaves {
        noise := gen_noise_single_2d(state, seed, x, y)
        seed  += 1
        sum   += noise * amp
        amp   *= lerp(1.0, math.min(noise + 1, 2) * 0.5, state.weighted_strength)

        x   *= FNL_Float(state.lacunarity)
        y   *= FNL_Float(state.lacunarity)
        amp *= state.gain
    }

    return sum
}

@private
gen_fractal_fbm_3d :: proc (state: FNL_State, x, y, z: FNL_Float) -> f32 {
    x := x; y := y; z := z
    seed := state.seed
    sum :f32= 0
    amp := calculate_fractal_bounding(state)

    for _ in 0..<state.octaves {
        noise := gen_noise_single_3d(state, seed, x, y, z)
        seed += 1
        sum += noise * amp
        amp *= lerp(1.0, (noise + 1) * 0.5, state.weighted_strength)

        y *= FNL_Float(state.lacunarity)
        z *= FNL_Float(state.lacunarity)
        x *= FNL_Float(state.lacunarity)
        amp *= state.gain
    }

    return sum
}

// Fractal Ridged

@private
gen_fractal_ridged_2d :: proc (state: FNL_State, x, y: FNL_Float) -> f32 {
    x := x; y := y
    seed := state.seed
    sum: f32 = 0
    amp := calculate_fractal_bounding(state)

    for  _ in 0..<state.octaves {
        noise := math.abs(gen_noise_single_2d(state, seed, x, y))
        seed += 1
        sum += (noise * -2 + 1) * amp
        amp *= lerp(1.0, 1 - noise, state.weighted_strength)

        x *= FNL_Float(state.lacunarity)
        y *= FNL_Float(state.lacunarity)
        amp *= state.gain
    }

    return sum
}

@private
gen_fractal_ridged_3d :: proc(state: FNL_State, x, y, z: FNL_Float) -> f32 {
    x := x; y := y; z := z
    seed := state.seed
    sum: f32 = 0
    amp := calculate_fractal_bounding(state)

    for _ in 0..<state.octaves {
        noise := math.abs(gen_noise_single_3d(state, seed, x, y, z))
        seed += 1
        sum += (noise * -2 + 1) * amp
        amp *= lerp(1.0, 1 - noise, state.weighted_strength)

        x *= FNL_Float(state.lacunarity)
        y *= FNL_Float(state.lacunarity)
        z *= FNL_Float(state.lacunarity)
        amp *= state.gain
    }

    return sum
}

// Fractal PingPong
@private
gen_fractal_ping_pong_2d :: proc (state: FNL_State, x, y: FNL_Float) -> f32 {
    x := x; y := y
    seed := state.seed
    sum: f32 = 0
    amp := calculate_fractal_bounding(state)

    for _ in 0..<state.octaves {
        noise := ping_pong((gen_noise_single_2d(state, seed, x, y) + 1) * state.ping_pong_strength)
        seed += 1
        sum += (noise - 0.5) * 2 * amp
        amp *= lerp(1.0, noise, state.weighted_strength)

        x *= FNL_Float(state.lacunarity)
        y *= FNL_Float(state.lacunarity)
        amp *= state.gain
    }

    return sum
}

@private
gen_fractal_ping_pong_3d :: proc (state: FNL_State, x, y, z: FNL_Float) -> f32 {
    x := x; y := y; z := z
    seed := state.seed
    sum: f32 = 0
    amp := calculate_fractal_bounding(state)

    for _ in 0..<state.octaves {
        noise := ping_pong((gen_noise_single_3d(state, seed, x, y, z) + 1) * state.ping_pong_strength)
        seed += 1
        sum += (noise - 0.5) * 2 * amp
        amp *= lerp(1.0, noise, state.weighted_strength)

        x *= FNL_Float(state.lacunarity)
        y *= FNL_Float(state.lacunarity)
        z *= FNL_Float(state.lacunarity)
        amp *= state.gain
    }

    return sum
}

// Simplex/OpenSimplex2 Noise

@private
single_simplex_2d :: proc (seed: i32, x, y: FNL_Float) -> f32 {
    // 2D OpenSimplex2 case uses the same algorithm as ordinary Simplex.

    SQRT3 : f32 : 1.7320508075688772935274463415059
    G2    : f32 : (3 - SQRT3) / 6

    i  := fast_floor(x)
    j  := fast_floor(y)
    xi := f32(x) - f32(i)
    yi := f32(y) - f32(j)

    t  := ((xi + yi) * G2)
    x0 := f32(xi - t)
    y0 := f32(yi - t)

    i  *= PRIME_X
    j  *= PRIME_Y

    n0, n1, n2: f32

    a := 0.5 - x0 * x0 - y0 * y0
    if a <= 0 do n0 = 0
    else do n0 = (a * a) * (a * a) * grad_coord_2d(seed, i, j, x0, y0)

    c := f32(2 * (1 - 2 * G2) * (1 / G2 - 2)) * t + (f32(-2 * (1 - 2 * G2) * (1 - 2 * G2)) + a)
    if c <= 0 do n2 = 0
    else {
        x2 := x0 + (2 * G2 - 1)
        y2 := y0 + (2 * G2 - 1)
        n2 = (c * c) * (c * c) * f32(grad_coord_2d(seed, i + PRIME_X, j + PRIME_Y, f32(x2), f32(y2)))
    }

    if y0 > x0 {
        x1 := x0 + G2
        y1 := y0 + (G2 - 1)
        b  := 0.5 - x1 * x1 - y1 * y1
        if b <= 0 do n1 = 0
        else do n1 = (b * b) * (b * b) * grad_coord_2d(seed, i, j + PRIME_Y, x1, y1)
    } else {
        x1 := x0 + (G2 - 1)
        y1 := y0 + G2
        b  := 0.5 - x1 * x1 - y1 * y1
        if b <= 0 do n1 = 0
        else do n1 = (b * b) * (b * b) * grad_coord_2d(seed, i + PRIME_X, j, x1, y1)
    }

    return (n0 + n1 + n2) * 99.83685446303647
}

@private
single_open_simplex2_3d :: proc (seed: i32, x, y, z: FNL_Float) -> f32 {
    // 3D OpenSimplex2 case uses two offset rotated cube grids.
    seed := seed

    i := fast_round(x)
    j := fast_round(y)
    k := fast_round(z)

    x0 := f32(x) - f32(i)
    y0 := f32(y) - f32(j)
    z0 := f32(z) - f32(k)

    xNSign := i32(-1.0 - x0) | 1
    yNSign := i32(-1.0 - y0) | 1
    zNSign := i32(-1.0 - z0) | 1

    ax0 := f32(xNSign) * -x0
    ay0 := f32(yNSign) * -y0
    az0 := f32(zNSign) * -z0

    i *= PRIME_X
    j *= PRIME_Y
    k *= PRIME_Z

    value: f32 = 0
    a:     f32 = (0.6 - x0 * x0) - (y0 * y0 + z0 * z0)

    for l := 0; ; l+=1 {
        if a > 0 do value += (a * a) * (a * a) * grad_coord_3d(seed, i, j, k, x0, y0, z0)

        b := a + 1
        i1 := i
        j1 := j
        k1 := k
        x1 := x0
        y1 := y0
        z1 := z0
        if ax0 >= ay0 && ax0 >= az0 {
            x1 += f32(xNSign)
            b  -= f32(xNSign) * 2 * x1
            i1 -= xNSign * PRIME_X
        } else if ay0 > ax0 && ay0 >= az0 {
            y1 += f32(yNSign)
            b  -= f32(yNSign) * 2 * y1
            j1 -= yNSign * PRIME_Y
        } else {
            z1 += f32(zNSign)
            b  -= f32(zNSign) * 2 * z1
            k1 -= zNSign * PRIME_Z
        }

        if b > 0 do value += (b * b) * (b * b) * grad_coord_3d(seed, i1, j1, k1, x1, y1, z1)

        if l == 1 do break

        ax0 = 0.5 - ax0
        ay0 = 0.5 - ay0
        az0 = 0.5 - az0

        x0 = f32(xNSign) * ax0
        y0 = f32(yNSign) * ay0
        z0 = f32(zNSign) * az0

        a += (0.75 - ax0) - (ay0 + az0)

        i += (xNSign >> 1) & PRIME_X
        j += (yNSign >> 1) & PRIME_Y
        k += (zNSign >> 1) & PRIME_Z

        xNSign = -xNSign
        yNSign = -yNSign
        zNSign = -zNSign

        seed = ~seed
    }

    return value * 32.69428253173828125
}

// OpenSimplex2S Noise

@private
single_open_simplex2s_2d :: proc (seed: i32, x, y: FNL_Float) -> f32 {
    // 2D OpenSimplex2S case is a modified 2D simplex noise.

    SQRT3 :: FNL_Float(1.7320508075688772935274463415059)
    G2 : FNL_Float : (3 - SQRT3) / 6

    i := fast_floor(x)
    j := fast_floor(y)
    xi := f32(x) - f32(i)
    yi := f32(y) - f32(j)
    
    i *= PRIME_X
    j *= PRIME_Y
    
    i1 := i + PRIME_X
    j1 := j + PRIME_Y
    
    t       := (xi + yi) * f32(G2)
    x0      := xi - t
    y0      := yi - t
    
    a0      := (2.0 / 3.0) - x0 * x0 - y0 * y0
    value   := (a0 * a0) * (a0 * a0) * grad_coord_2d(seed, i, j, x0, y0)
    
    a1      := f32(2 * (1 - 2 * G2) * (1 / G2 - 2)) * t + (f32(-2 * (1 - 2 * G2) * (1 - 2 * G2)) + a0)
    x1      := x0 - f32(1 - 2 * G2)
    y1      := y0 - f32(1 - 2 * G2)
    value   += (a1 * a1) * (a1 * a1) * grad_coord_2d(seed, i1, j1, x1, y1)

    // Nested conditionals were faster than compact bit logic/arithmetic.
    xmyi    := xi - yi
    if FNL_Float(t) > G2 {
        if xi + xmyi > 1 {
            x2 := x0 + f32(3 * G2 - 2)
            y2 := y0 + f32(3 * G2 - 1)
            a2 := (2.0 / 3.0) - x2 * x2 - y2 * y2
            if a2 > 0 do value += (a2 * a2) * (a2 * a2) * grad_coord_2d(seed, i + (PRIME_X << 1), j + PRIME_Y, x2, y2)
        } else {
            x2 := x0 + f32(G2)
            y2 := y0 + f32(G2 - 1)
            a2 := (2.0 / 3.0) - x2 * x2 - y2 * y2
            if a2 > 0 do value += (a2 * a2) * (a2 * a2) * grad_coord_2d(seed, i, j + PRIME_Y, x2, y2)
        }

        if yi - xmyi > 1 {
            x3 := x0 + f32(3 * G2 - 1)
            y3 := y0 + f32(3 * G2 - 2)
            a3 := (2.0 / 3.0) - x3 * x3 - y3 * y3
            if a3 > 0 do value += (a3 * a3) * (a3 * a3) * grad_coord_2d(seed, i + PRIME_X, j + (PRIME_Y << 1), x3, y3)
        } else {
            x3 := x0 + f32(G2 - 1)
            y3 := y0 + f32(G2)
            a3 := (2.0 / 3.0) - x3 * x3 - y3 * y3
            if a3 > 0 do value += (a3 * a3) * (a3 * a3) * grad_coord_2d(seed, i + PRIME_X, j, x3, y3)
        }
    } else {
        if xi + xmyi < 0 {
            x2 := x0 + f32(1 - G2)
            y2 := y0 - f32(G2)
            a2 := (2.0 / 3.0) - x2 * x2 - y2 * y2
            if a2 > 0 do value += (a2 * a2) * (a2 * a2) * grad_coord_2d(seed, i - PRIME_X, j, x2, y2)
        } else {
            x2 := x0 + f32(G2 - 1)
            y2 := y0 + f32(G2)
            a2 := (2.0 / 3.0) - x2 * x2 - y2 * y2
            if a2 > 0 do value += (a2 * a2) * (a2 * a2) * grad_coord_2d(seed, i + PRIME_X, j, x2, y2)
        }

        if yi < xmyi {
            x2 := x0 - f32(G2)
            y2 := y0 - f32(G2 - 1)
            a2 := (2.0 / 3.0) - x2 * x2 - y2 * y2
            if a2 > 0 do value += (a2 * a2) * (a2 * a2) * grad_coord_2d(seed, i, j - PRIME_Y, x2, y2)
        } else {
            x2 := x0 + f32(G2)
            y2 := y0 + f32(G2 - 1)
            a2 := (2.0 / 3.0) - x2 * x2 - y2 * y2
            if a2 > 0 do value += (a2 * a2) * (a2 * a2) * grad_coord_2d(seed, i, j + PRIME_Y, x2, y2)
        }
    }

    return value * 18.24196194486065
}

@private
single_open_simplex2s_3d :: proc(seed: i32, x, y, z: FNL_Float) -> f32 {
    // 3D OpenSimplex2S case uses two offset rotated cube grids.

    i := fast_floor(x)
    j := fast_floor(y)
    k := fast_floor(z)

    xi := f32(x) - f32(i)
    yi := f32(y) - f32(j)
    zi := f32(z) - f32(k)

    i *= PRIME_X
    j *= PRIME_Y
    k *= PRIME_Z
    seed2 := seed + 1293373

    xNMask := i32(-0.5 - xi)
    yNMask := i32(-0.5 - yi)
    zNMask := i32(-0.5 - zi)

    x0 := xi + f32(xNMask)
    y0 := yi + f32(yNMask)
    z0 := zi + f32(zNMask)
    a0 := 0.75 - x0 * x0 - y0 * y0 - z0 * z0
    value := (a0 * a0) * (a0 * a0) * grad_coord_3d(seed,
        i + (xNMask & PRIME_X), j + (yNMask & PRIME_Y), k + (zNMask & PRIME_Z), x0, y0, z0)

    x1 := xi - 0.5
    y1 := yi - 0.5
    z1 := zi - 0.5
    a1 := 0.75 - x1 * x1 - y1 * y1 - z1 * z1
    value += (a1 * a1) * (a1 * a1) * grad_coord_3d(seed2,
        i + PRIME_X, j + PRIME_Y, k + PRIME_Z, x1, y1, z1)

    xAFlipMask0 := f32((xNMask | 1) << 1) * x1
    yAFlipMask0 := f32((yNMask | 1) << 1) * y1
    zAFlipMask0 := f32((zNMask | 1) << 1) * z1
    xAFlipMask1 := f32(-2 - (xNMask << 2)) * x1 - 1.0
    yAFlipMask1 := f32(-2 - (yNMask << 2)) * y1 - 1.0
    zAFlipMask1 := f32(-2 - (zNMask << 2)) * z1 - 1.0

    skip5 := false
    a2 := xAFlipMask0 + a0
    if a2 > 0 {
        x2 := x0 - f32(xNMask | 1)
        y2 := y0
        z2 := z0
        value += (a2 * a2) * (a2 * a2) * grad_coord_3d(seed,
            i + (~xNMask & PRIME_X), j + (yNMask & PRIME_Y), k + (zNMask & PRIME_Z), x2, y2, z2)
    } else {
        a3 := yAFlipMask0 + zAFlipMask0 + a0
        if a3 > 0 {
            x3 := x0
            y3 := y0 - f32(yNMask | 1)
            z3 := z0 - f32(zNMask | 1)
            value += (a3 * a3) * (a3 * a3) * grad_coord_3d(seed,
                i + (xNMask & PRIME_X), j + (~yNMask & PRIME_Y), k + (~zNMask & PRIME_Z), x3, y3, z3)
        }

        a4 := xAFlipMask1 + a1
        if a4 > 0 {
            x4 := f32(xNMask | 1) + x1
            y4 := y1
            z4 := z1
            value += (a4 * a4) * (a4 * a4) * grad_coord_3d(seed2,
                i + (xNMask & (PRIME_X * 2)), j + PRIME_Y, k + PRIME_Z, x4, y4, z4)
            skip5 = true
        }
    }

    skip9 := false
    a6 := yAFlipMask0 + a0
    if a6 > 0 {
        x6 := x0
        y6 := y0 - f32(yNMask | 1)
        z6 := z0
        value += (a6 * a6) * (a6 * a6) * grad_coord_3d(seed,
            i + (xNMask & PRIME_X), j + (~yNMask & PRIME_Y), k + (zNMask & PRIME_Z), x6, y6, z6)
    } else {
        a7 := xAFlipMask0 + zAFlipMask0 + a0
        if a7 > 0 {
            x7 := x0 - f32(xNMask | 1)
            y7 := y0
            z7 := z0 - f32(zNMask | 1)
            value += (a7 * a7) * (a7 * a7) * grad_coord_3d(seed,
                i + (~xNMask & PRIME_X), j + (yNMask & PRIME_Y), k + (~zNMask & PRIME_Z), x7, y7, z7)
        }

        a8 := yAFlipMask1 + a1
        if a8 > 0 {
            x8 := x1
            y8 := f32(yNMask | 1) + y1
            z8 := z1
            value += (a8 * a8) * (a8 * a8) * grad_coord_3d(seed2,
                i + PRIME_X, j + (yNMask & (PRIME_Y << 1)), k + PRIME_Z, x8, y8, z8)
            skip9 = true
        }
    }

    skipD := false
    aA := zAFlipMask0 + a0
    if aA > 0 {
        xA := x0
        yA := y0
        zA := z0 - f32(zNMask | 1)
        value += (aA * aA) * (aA * aA) * grad_coord_3d(seed,
            i + (xNMask & PRIME_X), j + (yNMask & PRIME_Y), k + (~zNMask & PRIME_Z), xA, yA, zA)
    } else {
        aB := xAFlipMask0 + yAFlipMask0 + a0
        if aB > 0 {
            xB := x0 - f32(xNMask | 1)
            yB := y0 - f32(yNMask | 1)
            zB := z0
            value += (aB * aB) * (aB * aB) * grad_coord_3d(seed,
                i + (~xNMask & PRIME_X), j + (~yNMask & PRIME_Y), k + (zNMask & PRIME_Z), xB, yB, zB)
        }

        aC := zAFlipMask1 + a1
        if aC > 0 {
            xC := x1
            yC := y1
            zC := f32(zNMask | 1) + z1
            value += (aC * aC) * (aC * aC) * grad_coord_3d(seed2,
                i + PRIME_X, j + PRIME_Y, k + (zNMask & (PRIME_Z << 1)), xC, yC, zC)
            skipD = true
        }
    }

    if !skip5 {
        a5 := yAFlipMask1 + zAFlipMask1 + a1
        if a5 > 0 {
            x5 := x1
            y5 := f32(yNMask | 1) + y1
            z5 := f32(zNMask | 1) + z1
            value += (a5 * a5) * (a5 * a5) * grad_coord_3d(seed2,
                i + PRIME_X, j + (yNMask & (PRIME_Y << 1)), k + (zNMask & (PRIME_Z << 1)), x5, y5, z5)
        }
    }

    if !skip9 {
        a9 := xAFlipMask1 + zAFlipMask1 + a1
        if a9 > 0 {
            x9 := f32(xNMask | 1) + x1
            y9 := y1
            z9 := f32(zNMask | 1) + z1
            value += (a9 * a9) * (a9 * a9) * grad_coord_3d(seed2, 
                i + (xNMask & (PRIME_X * 2)), j + PRIME_Y, k + (zNMask & (PRIME_Z << 1)), x9, y9, z9)
        }
    }

    if !skipD {
        aD := xAFlipMask1 + yAFlipMask1 + a1
        if aD > 0 {
            xD := f32(xNMask | 1) + x1
            yD := f32(yNMask | 1) + y1
            zD := z1
            value += (aD * aD) * (aD * aD) * grad_coord_3d(seed2,
                i + (xNMask & (PRIME_X << 1)), j + (yNMask & (PRIME_Y << 1)), k + PRIME_Z, xD, yD, zD)
        }
    }

    return value * 9.046026385208288
}

// Cellular Noise

@private
single_cellular_2d :: proc (state: FNL_State, seed: i32, x, y: FNL_Float) -> f32 {
    xr := fast_round(x)
    yr := fast_round(y)

    distance0: f32 = math.F32_MAX
    distance1: f32 = math.F32_MAX
    closestHash: i32

    cellularJitter: f64 = 0.43701595 * f64(state.cellular_jitter_mod)

    xPrimed := (xr - 1) * PRIME_X
    yPrimedBase := (yr - 1) * PRIME_Y

    switch state.cellular_distance_func
    {
    case: fallthrough
    case .Euclidean,
         .Euclidean_SQ:
        for xi := xr - 1; xi <= xr + 1; xi += 1 {
            yPrimed := yPrimedBase

            for yi := yr - 1; yi <= yr + 1; yi += 1 {
                hash := hash_2d(seed, xPrimed, yPrimed)
                idx  := hash & (255 << 1)

                vecX := f32(xi) - f32(x) + f32(RAND_VECS_2D[idx] * cellularJitter)
                vecY := f32(yi) - f32(y) + f32(RAND_VECS_2D[idx | 1] * cellularJitter)

                newDistance := vecX * vecX + vecY * vecY

                distance1 = math.max(math.min(distance1, newDistance), distance0)
                if newDistance < distance0 {
                    distance0 = newDistance
                    closestHash = hash
                }
                yPrimed += PRIME_Y
            }
            xPrimed += PRIME_X
        }
    case .Manhattan:
        for xi := xr - 1; xi <= xr + 1; xi += 1 {
            yPrimed := yPrimedBase

            for yi := yr - 1; yi <= yr + 1; yi += 1 {
                hash := hash_2d(seed, xPrimed, yPrimed)
                idx := hash & (255 << 1)

                vecX := f32(xi) - f32(x) + f32(RAND_VECS_2D[idx] * cellularJitter)
                vecY := f32(yi) - f32(y) + f32(RAND_VECS_2D[idx | 1] * cellularJitter)

                newDistance := math.abs(vecX) + math.abs(vecY)

                distance1 = math.max(math.min(distance1, newDistance), distance0)
                if newDistance < distance0 {
                    distance0 = newDistance
                    closestHash = hash
                }
                yPrimed += PRIME_Y
            }
            xPrimed += PRIME_X
        }
    case .Hybrid:
        for xi := xr - 1; xi <= xr + 1; xi += 1 {
            yPrimed := yPrimedBase

            for yi := yr - 1; yi <= yr + 1; yi += 1 {
                hash := hash_2d(seed, xPrimed, yPrimed)
                idx := hash & (255 << 1)

                vecX := f32(xi) - f32(x) + f32(RAND_VECS_2D[idx] * cellularJitter)
                vecY := f32(yi) - f32(y) + f32(RAND_VECS_2D[idx | 1] * cellularJitter)

                newDistance := (math.abs(vecX) + math.abs(vecY)) + (vecX * vecX + vecY * vecY)

                distance1 = math.max(math.min(distance1, newDistance), distance0)
                if newDistance < distance0 {
                    distance0 = newDistance
                    closestHash = hash
                }
                yPrimed += PRIME_Y
            }
            xPrimed += PRIME_X
        }
    }

    if (state.cellular_distance_func == .Euclidean && state.cellular_return_type >= .Distance) {
        distance0 = fast_sqrt(distance0)
        if state.cellular_return_type >= .Distance2 do distance1 = fast_sqrt(distance1)
    }

    switch (state.cellular_return_type)
    {
    case .Cellvalue:
        return f32(closestHash) * (1.0 / 2147483648.0)
    case .Distance:
        return distance0 - 1
    case .Distance2:
        return distance1 - 1
    case .Distance2_Add:
        return (distance1 + distance0) * 0.5 - 1
    case .Distance2_Sub:
        return distance1 - distance0 - 1
    case .Distance2_Mul:
        return distance1 * distance0 * 0.5 - 1
    case .Distance2_Div:
        return distance0 / distance1 - 1
    case:
        return 0
    }
}

@private
single_cellular_3d :: proc (state: FNL_State, seed: i32, x, y, z: FNL_Float) -> f32 {
    xr := fast_round(x)
    yr := fast_round(y)
    zr := fast_round(z)

    distance0: f32 = math.F32_MAX
    distance1: f32 = math.F32_MAX
    closestHash: i32

    cellularJitter: f64 = 0.39614353 * f64(state.cellular_jitter_mod)

    xPrimed := (xr - 1) * PRIME_X
    yPrimedBase := (yr - 1) * PRIME_Y
    zPrimedBase := (zr - 1) * PRIME_Z

    switch (state.cellular_distance_func)
    {
    case: fallthrough
    case .Euclidean, 
    .Euclidean_SQ:
        for xi := xr - 1; xi <= xr + 1; xi += 1 {
            yPrimed := yPrimedBase

            for yi := yr - 1; yi <= yr + 1; yi += 1 {
                zPrimed := zPrimedBase

                for zi := zr - 1; zi <= zr + 1; zi += 1 {
                    hash := hash_3d(seed, xPrimed, yPrimed, zPrimed)
                    idx := hash & (255 << 2)

                    vecX := f32(xi) - f32(x) + f32(RAND_VECS_3D[idx] * cellularJitter)
                    vecY := f32(yi) - f32(y) + f32(RAND_VECS_3D[idx | 1] * cellularJitter)
                    vecZ := f32(zi) - f32(z) + f32(RAND_VECS_3D[idx | 2] * cellularJitter)

                    newDistance := vecX * vecX + vecY * vecY + vecZ * vecZ

                    distance1 = math.max(math.min(distance1, newDistance), distance0)
                    if newDistance < distance0 {
                        distance0 = newDistance
                        closestHash = hash
                    }
                    zPrimed += PRIME_Z
                }
                yPrimed += PRIME_Y
            }
            xPrimed += PRIME_X
        }
    case .Manhattan:
        for xi := xr - 1; xi <= xr + 1; xi += 1 {
            yPrimed := yPrimedBase

            for yi := yr - 1; yi <= yr + 1; yi += 1 {
                zPrimed := zPrimedBase

                for zi := zr - 1; zi <= zr + 1; zi += 1 {
                    hash := hash_3d(seed, xPrimed, yPrimed, zPrimed)
                    idx := hash & (255 << 2)

                    vecX := f32(xi) - f32(x) + f32(RAND_VECS_3D[idx] * cellularJitter)
                    vecY := f32(yi) - f32(y) + f32(RAND_VECS_3D[idx | 1] * cellularJitter)
                    vecZ := f32(zi) - f32(z) + f32(RAND_VECS_3D[idx | 2] * cellularJitter)

                    newDistance := math.abs(vecX) + math.abs(vecY) + math.abs(vecZ)

                    distance1 = math.max(math.min(distance1, newDistance), distance0)
                    if newDistance < distance0 {
                        distance0 = newDistance
                        closestHash = hash
                    }
                    zPrimed += PRIME_Z
                }
                yPrimed += PRIME_Y
            }
            xPrimed += PRIME_X
        }
    case .Hybrid:
        for xi := xr - 1; xi <= xr + 1; xi += 1 {
            yPrimed := yPrimedBase

            for yi := yr - 1; yi <= yr + 1; yi += 1 {
                zPrimed := zPrimedBase

                for zi := zr - 1; zi <= zr + 1; zi += 1 {
                    hash := hash_3d(seed, xPrimed, yPrimed, zPrimed)
                    idx := hash & (255 << 2)

                    vecX := f32(xi) - f32(x) + f32(RAND_VECS_3D[idx] * cellularJitter)
                    vecY := f32(yi) - f32(y) + f32(RAND_VECS_3D[idx | 1] * cellularJitter)
                    vecZ := f32(zi) - f32(z) + f32(RAND_VECS_3D[idx | 2] * cellularJitter)

                    newDistance := (math.abs(vecX) + math.abs(vecY) + math.abs(vecZ)) + (vecX * vecX + vecY * vecY + vecZ * vecZ)

                    distance1 = math.max(math.min(distance1, newDistance), distance0)
                    if newDistance < distance0 {
                        distance0 = newDistance
                        closestHash = hash
                    }
                    zPrimed += PRIME_Z
                }
                yPrimed += PRIME_Y
            }
            xPrimed += PRIME_X
        }
    }

    if state.cellular_distance_func == .Euclidean &&
    state.cellular_return_type >= .Distance {
        distance0 = fast_sqrt(distance0)
        if state.cellular_return_type >= .Distance2 do distance1 = fast_sqrt(distance1)
    }

    switch (state.cellular_return_type)
    {
    case .Cellvalue:
        return f32(closestHash) * (1 / 2147483648.0)
    case .Distance:
        return distance0 - 1
    case .Distance2:
        return distance1 - 1
    case .Distance2_Add:
        return (distance1 + distance0) * 0.5 - 1
    case .Distance2_Sub:
        return distance1 - distance0 - 1
    case .Distance2_Mul:
        return distance1 * distance0 * 0.5 - 1
    case .Distance2_Div:
        return distance0 / distance1 - 1
    case:
        return 0
    }
}
// Perlin Noise

@private
single_perlin_2d :: proc (seed: i32, x, y: FNL_Float) -> f32 {
    x0 := fast_floor(x)
    y0 := fast_floor(y)

    xd0 := f32(x) - f32(x0)
    yd0 := f32(y) - f32(y0)
    xd1 := xd0 - 1
    yd1 := yd0 - 1

    xs := i32erp_qui32ic(xd0)
    ys := i32erp_qui32ic(yd0)

    x0 *= PRIME_X
    y0 *= PRIME_Y
    x1 := x0 + PRIME_X
    y1 := y0 + PRIME_Y

    xf0 := lerp(grad_coord_2d(seed, x0, y0, xd0, yd0), grad_coord_2d(seed, x1, y0, xd1, yd0), xs)
    xf1 := lerp(grad_coord_2d(seed, x0, y1, xd0, yd1), grad_coord_2d(seed, x1, y1, xd1, yd1), xs)

    return lerp(xf0, xf1, ys) * 1.4247691104677813
}

@private
single_perlin_3d :: proc (seed: i32, x, y, z: FNL_Float) -> f32 {
    x0 := fast_floor(x)
    y0 := fast_floor(y)
    z0 := fast_floor(z)

    xd0 := f32(x) - f32(x0)
    yd0 := f32(y) - f32(y0)
    zd0 := f32(z) - f32(z0)
    xd1 := xd0 - 1
    yd1 := yd0 - 1
    zd1 := zd0 - 1

    xs := i32erp_qui32ic(xd0)
    ys := i32erp_qui32ic(yd0)
    zs := i32erp_qui32ic(zd0)

    x0 *= PRIME_X
    y0 *= PRIME_Y
    z0 *= PRIME_Z
    x1 := x0 + PRIME_X
    y1 := y0 + PRIME_Y
    z1 := z0 + PRIME_Z

    xf00 := lerp(grad_coord_3d(seed, x0, y0, z0, xd0, yd0, zd0), grad_coord_3d(seed, x1, y0, z0, xd1, yd0, zd0), xs)
    xf10 := lerp(grad_coord_3d(seed, x0, y1, z0, xd0, yd1, zd0), grad_coord_3d(seed, x1, y1, z0, xd1, yd1, zd0), xs)
    xf01 := lerp(grad_coord_3d(seed, x0, y0, z1, xd0, yd0, zd1), grad_coord_3d(seed, x1, y0, z1, xd1, yd0, zd1), xs)
    xf11 := lerp(grad_coord_3d(seed, x0, y1, z1, xd0, yd1, zd1), grad_coord_3d(seed, x1, y1, z1, xd1, yd1, zd1), xs)

    yf0 := lerp(xf00, xf10, ys)
    yf1 := lerp(xf01, xf11, ys)

    return lerp(yf0, yf1, zs) * 0.964921414852142333984375
}

// Value Cubic

@private
single_value_cubic_2d :: proc (seed: i32, x, y: FNL_Float) -> f32 {
    x1 := fast_floor(x)
    y1 := fast_floor(y)

    xs := f32(x) - f32(x1)
    ys := f32(y) - f32(y1)

    x1 *= PRIME_X
    y1 *= PRIME_Y

    x0 := x1 - PRIME_X
    y0 := y1 - PRIME_Y
    x2 := x1 + PRIME_X
    y2 := y1 + PRIME_Y
    x3 := x1 + i32(i64(PRIME_X) << 1)
    y3 := y1 + i32(i64(PRIME_Y) << 1)

    return cubic_lerp(
        cubic_lerp(val_coord_2d(seed, x0, y0), val_coord_2d(seed, x1, y0), val_coord_2d(seed, x2, y0), val_coord_2d(seed, x3, y0),
                      xs),
        cubic_lerp(val_coord_2d(seed, x0, y1), val_coord_2d(seed, x1, y1), val_coord_2d(seed, x2, y1), val_coord_2d(seed, x3, y1),
                      xs),
        cubic_lerp(val_coord_2d(seed, x0, y2), val_coord_2d(seed, x1, y2), val_coord_2d(seed, x2, y2), val_coord_2d(seed, x3, y2),
                      xs),
        cubic_lerp(val_coord_2d(seed, x0, y3), val_coord_2d(seed, x1, y3), val_coord_2d(seed, x2, y3), val_coord_2d(seed, x3, y3),
                      xs),
        ys) * (1 / (1.5 * 1.5))
}

@private
single_value_cubic_3d :: proc (seed: i32, x, y, z: FNL_Float) -> f32 {
    x1 := fast_floor(x)
    y1 := fast_floor(y)
    z1 := fast_floor(z)

    xs := f32(x) - f32(x1)
    ys := f32(y) - f32(y1)
    zs := f32(z) - f32(z1)

    x1 *= PRIME_X
    y1 *= PRIME_Y
    z1 *= PRIME_Z

    x0 := x1 - PRIME_X
    y0 := y1 - PRIME_Y
    z0 := z1 - PRIME_Z
    x2 := x1 + PRIME_X
    y2 := y1 + PRIME_Y
    z2 := z1 + PRIME_Z
    x3 := x1 + i32(i64(PRIME_X) << 1)
    y3 := y1 + i32(i64(PRIME_Y) << 1)
    z3 := z1 + i32(i64(PRIME_Z) << 1)

    return cubic_lerp(
        cubic_lerp(
            cubic_lerp(val_coord_3D(seed, x0, y0, z0), val_coord_3D(seed, x1, y0, z0), val_coord_3D(seed, x2, y0, z0), val_coord_3D(seed, x3, y0, z0), xs),
            cubic_lerp(val_coord_3D(seed, x0, y1, z0), val_coord_3D(seed, x1, y1, z0), val_coord_3D(seed, x2, y1, z0), val_coord_3D(seed, x3, y1, z0), xs),
            cubic_lerp(val_coord_3D(seed, x0, y2, z0), val_coord_3D(seed, x1, y2, z0), val_coord_3D(seed, x2, y2, z0), val_coord_3D(seed, x3, y2, z0), xs),
            cubic_lerp(val_coord_3D(seed, x0, y3, z0), val_coord_3D(seed, x1, y3, z0), val_coord_3D(seed, x2, y3, z0), val_coord_3D(seed, x3, y3, z0), xs),
            ys),
        cubic_lerp(
            cubic_lerp(val_coord_3D(seed, x0, y0, z1), val_coord_3D(seed, x1, y0, z1), val_coord_3D(seed, x2, y0, z1), val_coord_3D(seed, x3, y0, z1), xs),
            cubic_lerp(val_coord_3D(seed, x0, y1, z1), val_coord_3D(seed, x1, y1, z1), val_coord_3D(seed, x2, y1, z1), val_coord_3D(seed, x3, y1, z1), xs),
            cubic_lerp(val_coord_3D(seed, x0, y2, z1), val_coord_3D(seed, x1, y2, z1), val_coord_3D(seed, x2, y2, z1), val_coord_3D(seed, x3, y2, z1), xs),
            cubic_lerp(val_coord_3D(seed, x0, y3, z1), val_coord_3D(seed, x1, y3, z1), val_coord_3D(seed, x2, y3, z1), val_coord_3D(seed, x3, y3, z1), xs),
            ys),
        cubic_lerp(
            cubic_lerp(val_coord_3D(seed, x0, y0, z2), val_coord_3D(seed, x1, y0, z2), val_coord_3D(seed, x2, y0, z2), val_coord_3D(seed, x3, y0, z2), xs),
            cubic_lerp(val_coord_3D(seed, x0, y1, z2), val_coord_3D(seed, x1, y1, z2), val_coord_3D(seed, x2, y1, z2), val_coord_3D(seed, x3, y1, z2), xs),
            cubic_lerp(val_coord_3D(seed, x0, y2, z2), val_coord_3D(seed, x1, y2, z2), val_coord_3D(seed, x2, y2, z2), val_coord_3D(seed, x3, y2, z2), xs),
            cubic_lerp(val_coord_3D(seed, x0, y3, z2), val_coord_3D(seed, x1, y3, z2), val_coord_3D(seed, x2, y3, z2), val_coord_3D(seed, x3, y3, z2), xs),
            ys),
        cubic_lerp(
            cubic_lerp(val_coord_3D(seed, x0, y0, z3), val_coord_3D(seed, x1, y0, z3), val_coord_3D(seed, x2, y0, z3), val_coord_3D(seed, x3, y0, z3), xs),
            cubic_lerp(val_coord_3D(seed, x0, y1, z3), val_coord_3D(seed, x1, y1, z3), val_coord_3D(seed, x2, y1, z3), val_coord_3D(seed, x3, y1, z3), xs),
            cubic_lerp(val_coord_3D(seed, x0, y2, z3), val_coord_3D(seed, x1, y2, z3), val_coord_3D(seed, x2, y2, z3), val_coord_3D(seed, x3, y2, z3), xs),
            cubic_lerp(val_coord_3D(seed, x0, y3, z3), val_coord_3D(seed, x1, y3, z3), val_coord_3D(seed, x2, y3, z3), val_coord_3D(seed, x3, y3, z3), xs),
            ys),
        zs) * (1 / 1.5 * 1.5 * 1.5)
}

// Value noise

@private
single_value_2d :: proc(seed: i32, x, y: FNL_Float) -> f32 {
    x0 := fast_floor(x)
    y0 := fast_floor(y)

    xs := i32erp_hermite(f32(x) - f32(x0))
    ys := i32erp_hermite(f32(y) - f32(y0))

    x0 *= PRIME_X
    y0 *= PRIME_Y
    x1 := x0 + PRIME_X
    y1 := y0 + PRIME_Y

    xf0 := lerp(val_coord_2d(seed, x0, y0), val_coord_2d(seed, x1, y0), xs)
    xf1 := lerp(val_coord_2d(seed, x0, y1), val_coord_2d(seed, x1, y1), xs)

    return lerp(xf0, xf1, ys)
}

@private
single_value_3d :: proc (seed: i32, x, y, z: FNL_Float) -> f32  {
    x0 := fast_floor(x)
    y0 := fast_floor(y)
    z0 := fast_floor(z)

    xs := i32erp_hermite(f32(x) - f32(x0))
    ys := i32erp_hermite(f32(y) - f32(y0))
    zs := i32erp_hermite(f32(z) - f32(z0))

    x0 *= PRIME_X
    y0 *= PRIME_Y
    z0 *= PRIME_Z
    x1 := x0 + PRIME_X
    y1 := y0 + PRIME_Y
    z1 := z0 + PRIME_Z

    xf00 := lerp(val_coord_3D(seed, x0, y0, z0), val_coord_3D(seed, x1, y0, z0), xs)
    xf10 := lerp(val_coord_3D(seed, x0, y1, z0), val_coord_3D(seed, x1, y1, z0), xs)
    xf01 := lerp(val_coord_3D(seed, x0, y0, z1), val_coord_3D(seed, x1, y0, z1), xs)
    xf11 := lerp(val_coord_3D(seed, x0, y1, z1), val_coord_3D(seed, x1, y1, z1), xs)

    yf0 := lerp(xf00, xf10, ys)
    yf1 := lerp(xf01, xf11, ys)

    return lerp(yf0, yf1, zs)
}

// Domain Warp
@private
do_single_domain_warp_2d :: #force_inline proc (
    state: FNL_State,
    seed: i32,
    amp, freq: f32,
    x, y: FNL_Float,
    xp, yp: ^FNL_Float,
) {
    switch (state.domain_warp_type)
    {
    case .Open_Simplex_2:
        single_domain_warp_simplex_gradient(seed, amp * 38.283687591552734375, freq, x, y, xp, yp, false)
    case .Open_Simplex_2_Reduced:
        single_domain_warp_simplex_gradient(seed, amp * 16.0, freq, x, y, xp, yp, true)
    case .Basic_Grid:
        single_domain_warp_basic_grid_2d(seed, amp, freq, x, y, xp, yp)
    }
}

@private
do_single_domain_warp_3d :: #force_inline proc (
    state: FNL_State,
    seed: i32,
    amp, freq: f32,
    x, y, z: FNL_Float,
    xp, yp, zp: ^FNL_Float,
) {
    switch (state.domain_warp_type)
    {
    case .Open_Simplex_2:
        single_domain_warp_open_simplex2_gradient(seed, amp * 32.69428253173828125, freq, x, y, z, xp, yp, zp, false)
    case .Open_Simplex_2_Reduced:
        single_domain_warp_open_simplex2_gradient(seed, amp * 7.71604938271605, freq, x, y, z, xp, yp, zp, true)
    case .Basic_Grid:
        single_domain_warp_basic_grid_3d(seed, amp, freq, x, y, z, xp, yp, zp)
    }
}

// Domain Warp Single Wrapper

@private
domain_warp_single_2d :: proc (state: FNL_State, x, y: ^FNL_Float) {
    seed := state.seed
    amp := state.domain_warp_amp * calculate_fractal_bounding(state)
    freq := state.frequency

    xs := x^
    ys := y^
    transform_domain_warp_coordinate_2d(state, &xs, &ys)

    do_single_domain_warp_2d(state, seed, amp, freq, xs, ys, x, y)
}

@private
domain_warp_single_3d :: proc (state: FNL_State, x, y, z: ^FNL_Float) {
    seed := state.seed
    amp := state.domain_warp_amp * calculate_fractal_bounding(state)
    freq := state.frequency

    xs := x^
    ys := y^
    zs := z^
    transform_domain_warp_coordinate_3d(state, &xs, &ys, &zs)

    do_single_domain_warp_3d(state, seed, amp, freq, xs, ys, zs, x, y, z)
}

// Domain Warp Fractal Progressive

@private
domain_warp_fractal_progressive_2d :: proc (state: FNL_State, x, y: ^FNL_Float) {
    seed := state.seed
    amp := state.domain_warp_amp * calculate_fractal_bounding(state)
    freq := state.frequency

    
    for i: i32 = 0; i < state.octaves; i += 1 {
        xs := x^
        ys := y^
        transform_domain_warp_coordinate_2d(state, &xs, &ys)

        do_single_domain_warp_2d(state, seed, amp, freq, xs, ys, x, y)

        seed +=1
        amp *= state.gain
        freq *= state.lacunarity
    }
}


@private
domain_warp_fractal_progressive_3d :: proc (state: FNL_State, x, y, z: ^FNL_Float) {
    seed := state.seed
    amp := state.domain_warp_amp * calculate_fractal_bounding(state)
    freq := state.frequency

    for i: i32 = 0; i < state.octaves; i += 1 {
        xs := x^
        ys := y^
        zs := z^
        transform_domain_warp_coordinate_3d(state, &xs, &ys, &zs)

        do_single_domain_warp_3d(state, seed, amp, freq, xs, ys, zs, x, y, z)

        seed +=1
        amp *= state.gain
        freq *= state.lacunarity
    }
}

// Domain Warp Fractal Independent

@private
domain_warp_fractal_independent_2d :: proc (state: FNL_State, x, y: ^FNL_Float) {
    xs := x^
    ys := y^
    transform_domain_warp_coordinate_2d(state, &xs, &ys)

    seed := state.seed
    amp := state.domain_warp_amp * calculate_fractal_bounding(state)
    freq := state.frequency

    for i: i32 = 0; i < state.octaves; i += 1 {
        do_single_domain_warp_2d(state, seed, amp, freq, xs, ys, x, y)

        seed +=1
        amp *= state.gain
        freq *= state.lacunarity
    }
}

@private
domain_warp_fractal_independent_3d :: proc (state: FNL_State, x, y, z: ^FNL_Float) {
    xs := x^
    ys := y^
    zs := z^
    transform_domain_warp_coordinate_3d(state, &xs, &ys, &zs)

    seed := state.seed
    amp := state.domain_warp_amp * calculate_fractal_bounding(state)
    freq := state.frequency

    for i: i32 = 0; i < state.octaves; i += 1 {
        do_single_domain_warp_3d(state, seed, amp, freq, xs, ys, zs, x, y, z)

        seed +=1
        amp *= state.gain
        freq *= state.lacunarity
    }
}

// Domain Warp Basic Grid

@private
single_domain_warp_basic_grid_2d :: proc (
    seed: i32,
    warpAmp, frequency: f32,
    x, y: FNL_Float,
    xp, yp: ^FNL_Float,
) {
    xf := x * FNL_Float(frequency)
    yf := y * FNL_Float(frequency)

    x0 := fast_floor(xf)
    y0 := fast_floor(yf)

    xs := i32erp_hermite(f32(xf) - f32(x0))
    ys := i32erp_hermite(f32(yf) - f32(y0))

    x0 *= PRIME_X
    y0 *= PRIME_Y
    x1 := x0 + PRIME_X
    y1 := y0 + PRIME_Y

    idx0 := hash_2d(seed, x0, y0) & (255 << 1)
    idx1 := hash_2d(seed, x1, y0) & (255 << 1)

    lx0x := lerp(f32(RAND_VECS_2D[idx0]), f32(RAND_VECS_2D[idx1]), xs)
    ly0x := lerp(f32(RAND_VECS_2D[idx0 | 1]), f32(RAND_VECS_2D[idx1 | 1]), xs)

    idx0 = hash_2d(seed, x0, y1) & (255 << 1)
    idx1 = hash_2d(seed, x1, y1) & (255 << 1)

    lx1x := lerp(f32(RAND_VECS_2D[idx0]), f32(RAND_VECS_2D[idx1]), xs)
    ly1x := lerp(f32(RAND_VECS_2D[idx0 | 1]), f32(RAND_VECS_2D[idx1 | 1]), xs)

    xp^ += FNL_Float(lerp(lx0x, lx1x, ys) * warpAmp)
    yp^ += FNL_Float(lerp(ly0x, ly1x, ys) * warpAmp)
}

@private
single_domain_warp_basic_grid_3d :: proc (
    seed: i32,
    warpAmp, frequency: f32,
    x, y, z: FNL_Float,
    xp, yp, zp: ^FNL_Float,
) {
    xf := x * FNL_Float(frequency)
    yf := y * FNL_Float(frequency)
    zf := z * FNL_Float(frequency)

    x0 := fast_floor(xf)
    y0 := fast_floor(yf)
    z0 := fast_floor(zf)

    xs := i32erp_hermite(f32(xf) - f32(x0))
    ys := i32erp_hermite(f32(yf) - f32(y0))
    zs := i32erp_hermite(f32(zf) - f32(z0))

    x0 *= PRIME_X
    y0 *= PRIME_Y
    z0 *= PRIME_Z
    x1 := x0 + PRIME_X
    y1 := y0 + PRIME_Y
    z1 := z0 + PRIME_Z

    idx0 := hash_3d(seed, x0, y0, z0) & (255 << 2)
    idx1 := hash_3d(seed, x1, y0, z0) & (255 << 2)

    lx0x := lerp(f32(RAND_VECS_3D[idx0]), f32(RAND_VECS_3D[idx1]), xs)
    ly0x := lerp(f32(RAND_VECS_3D[idx0 | 1]), f32(RAND_VECS_3D[idx1 | 1]), xs)
    lz0x := lerp(f32(RAND_VECS_3D[idx0 | 2]), f32(RAND_VECS_3D[idx1 | 2]), xs)

    idx0 = hash_3d(seed, x0, y1, z0) & (255 << 2)
    idx1 = hash_3d(seed, x1, y1, z0) & (255 << 2)

    lx1x := lerp(f32(RAND_VECS_3D[idx0]), f32(RAND_VECS_3D[idx1]), xs)
    ly1x := lerp(f32(RAND_VECS_3D[idx0 | 1]), f32(RAND_VECS_3D[idx1 | 1]), xs)
    lz1x := lerp(f32(RAND_VECS_3D[idx0 | 2]), f32(RAND_VECS_3D[idx1 | 2]), xs)

    lx0y := lerp(lx0x, lx1x, ys)
    ly0y := lerp(ly0x, ly1x, ys)
    lz0y := lerp(lz0x, lz1x, ys)

    idx0 = hash_3d(seed, x0, y0, z1) & (255 << 2)
    idx1 = hash_3d(seed, x1, y0, z1) & (255 << 2)

    lx0x = lerp(f32(RAND_VECS_3D[idx0]), f32(RAND_VECS_3D[idx1]), xs)
    ly0x = lerp(f32(RAND_VECS_3D[idx0 | 1]), f32(RAND_VECS_3D[idx1 | 1]), xs)
    lz0x = lerp(f32(RAND_VECS_3D[idx0 | 2]), f32(RAND_VECS_3D[idx1 | 2]), xs)

    idx0 = hash_3d(seed, x0, y1, z1) & (255 << 2)
    idx1 = hash_3d(seed, x1, y1, z1) & (255 << 2)

    lx1x = lerp(f32(RAND_VECS_3D[idx0]), f32(RAND_VECS_3D[idx1]), xs)
    ly1x = lerp(f32(RAND_VECS_3D[idx0 | 1]), f32(RAND_VECS_3D[idx1 | 1]), xs)
    lz1x = lerp(f32(RAND_VECS_3D[idx0 | 2]), f32(RAND_VECS_3D[idx1 | 2]), xs)

    xp^ += FNL_Float(lerp(lx0y, lerp(lx0x, lx1x, ys), zs) * warpAmp)
    yp^ += FNL_Float(lerp(ly0y, lerp(ly0x, ly1x, ys), zs) * warpAmp)
    zp^ += FNL_Float(lerp(lz0y, lerp(lz0x, lz1x, ys), zs) * warpAmp)
}

// Domain Warp Simplex/OpenSimplex2

@private
single_domain_warp_simplex_gradient :: proc (
    seed: i32,
    warpAmp, frequency: f32,
    x, y: FNL_Float,
    xr, yr: ^FNL_Float,
    outGradOnly: bool,
) {
    SQRT3 : f32 : 1.7320508075688772935274463415059
    G2    : f32 : (3 - SQRT3) / 6

    x := x; y := y
    x *= FNL_Float(frequency)
    y *= FNL_Float(frequency)

    i := fast_floor(x)
    j := fast_floor(y)
    xi := f32(x) - f32(i)
    yi := f32(y) - f32(j)

    t := (xi + yi) * G2
    x0 := f32(xi - t)
    y0 := f32(yi - t)

    i *= PRIME_X
    j *= PRIME_Y

    vx, vy: f32

    a := 0.5 - x0 * x0 - y0 * y0
    if a > 0 {
        aaaa := (a * a) * (a * a)
        xo, yo: f32
        if outGradOnly do grad_coord_out_2d(seed, i, j, &xo, &yo)
        else do grad_coord_dual_2d(seed, i, j, x0, y0, &xo, &yo)
        vx += aaaa * xo
        vy += aaaa * yo
    }

    c := f32(2 * (1 - 2 * G2) * (1 / G2 - 2)) * t + (f32(-2 * (1 - 2 * G2) * (1 - 2 * G2)) + a)
    if c > 0 {
        x2 := x0 + (2 * G2 - 1)
        y2 := y0 + (2 * G2 - 1)
        cccc := (c * c) * (c * c)
        xo, yo: f32
        if outGradOnly do grad_coord_out_2d(seed, i + PRIME_X, j + PRIME_Y, &xo, &yo)
        else do grad_coord_dual_2d(seed, i + PRIME_X, j + PRIME_Y, x2, y2, &xo, &yo)
        vx += cccc * xo
        vy += cccc * yo
    }

    if y0 > x0 {
        x1 := x0 + G2
        y1 := y0 + (G2 - 1)
        b := 0.5 - x1 * x1 - y1 * y1
        if b > 0 {
            bbbb := (b * b) * (b * b)
            xo, yo: f32
            if outGradOnly do grad_coord_out_2d(seed, i, j + PRIME_Y, &xo, &yo)
            else do grad_coord_dual_2d(seed, i, j + PRIME_Y, x1, y1, &xo, &yo)
            vx += bbbb * xo
            vy += bbbb * yo
        }
    } else{
        x1 := x0 + (G2 - 1)
        y1 := y0 + G2
        b := 0.5 - x1 * x1 - y1 * y1
        if b > 0 {
            bbbb := (b * b) * (b * b)
            xo, yo: f32
            if outGradOnly do grad_coord_out_2d(seed, i + PRIME_X, j, &xo, &yo)
            else do grad_coord_dual_2d(seed, i + PRIME_X, j, x1, y1, &xo, &yo)
            vx += bbbb * xo
            vy += bbbb * yo
        }
    }

    xr^ += FNL_Float(vx * warpAmp)
    yr^ += FNL_Float(vy * warpAmp)
}

@private
single_domain_warp_open_simplex2_gradient :: proc (
    seed: i32,
    warpAmp, frequency: f32,
    x, y, z: FNL_Float,
    xr, yr, zr: ^FNL_Float,
    outGradOnly: bool,
) {
    seed := seed; x := x; y := y; z := z
    
    x *= FNL_Float(frequency)
    y *= FNL_Float(frequency)
    z *= FNL_Float(frequency)

    i := fast_round(x)
    j := fast_round(y)
    k := fast_round(z)
    x0 := f32(x) - f32(i)
    y0 := f32(y) - f32(j)
    z0 := f32(z) - f32(k)

    xNSign := i32(-x0 - 1.0) | 1
    yNSign := i32(-y0 - 1.0) | 1
    zNSign := i32(-z0 - 1.0) | 1

    ax0 := f32(xNSign) * -x0
    ay0 := f32(yNSign) * -y0
    az0 := f32(zNSign) * -z0

    i *= PRIME_X
    j *= PRIME_Y
    k *= PRIME_Z

    vx, vy, vz: f32

    a :f32= (0.6 - x0 * x0) - (y0 * y0 + z0 * z0)
    
    for l:=0; l < 2; l +=1 {
        if a > 0 {
            aaaa := (a * a) * (a * a)
            xo, yo, zo: f32
            if outGradOnly do grad_coord_out_3d(seed, i, j, k, &xo, &yo, &zo)
            else do grad_coord_dual_3d(seed, i, j, k, x0, y0, z0, &xo, &yo, &zo)
            vx += aaaa * xo
            vy += aaaa * yo
            vz += aaaa * zo
        }

        b := a + 1
        i1 := i
        j1 := j
        k1 := k
        x1 := x0
        y1 := y0
        z1 := z0
        if ax0 >= ay0 && ax0 >= az0 {
            x1 += f32(xNSign)
            b -= f32(xNSign) * 2 * x1
            i1 -= xNSign * PRIME_X
        } else if ay0 > ax0 && ay0 >= az0 {
            y1 += f32(yNSign)
            b -= f32(yNSign) * 2 * y1
            j1 -= yNSign * PRIME_Y
        } else {
            z1 += f32(zNSign)
            b -= f32(zNSign) * 2 * z1
            k1 -= zNSign * PRIME_Z
        }

        if b > 0 {
            bbbb := (b * b) * (b * b)
            xo, yo, zo: f32
            if outGradOnly do grad_coord_out_3d(seed, i1, j1, k1, &xo, &yo, &zo)
            else do grad_coord_dual_3d(seed, i1, j1, k1, x1, y1, z1, &xo, &yo, &zo)
            vx += bbbb * xo
            vy += bbbb * yo
            vz += bbbb * zo
        }

        if l == 1 do break

        ax0 = 0.5 - ax0
        ay0 = 0.5 - ay0
        az0 = 0.5 - az0

        x0 = f32(xNSign) * ax0
        y0 = f32(yNSign) * ay0
        z0 = f32(zNSign) * az0

        a += (0.75 - ax0) - (ay0 + az0)

        i += (xNSign >> 1) & PRIME_X
        j += (yNSign >> 1) & PRIME_Y
        k += (zNSign >> 1) & PRIME_Z

        xNSign = -xNSign
        yNSign = -yNSign
        zNSign = -zNSign

        seed += 1293373
    }

    xr^ += FNL_Float(vx * warpAmp)
    yr^ += FNL_Float(vy * warpAmp)
    zr^ += FNL_Float(vz * warpAmp)
}

// ====================
// Public API
// ====================
create_state :: proc(seed: i32 = 1337) -> FNL_State {
    return {
        seed                   = seed,
        frequency              = 0.01,
        noise_type             = .Open_Simplex_2,
        rotation_type_3d       = .None,
        fractal_type           = .None,
        octaves                = 3,
        lacunarity             = 2.0,
        gain                   = 0.5,
        weighted_strength      = 0.0,
        ping_pong_strength     = 2.0,
        cellular_distance_func = .Euclidean_SQ,
        cellular_return_type   = .Distance,
        cellular_jitter_mod    = 1.0,
        domain_warp_amp        = 30.0,
        domain_warp_type       = .Open_Simplex_2,
    }
}


get_noise_2d :: proc (state: FNL_State, x, y: FNL_Float) -> f32 {
    x := x; y := y
    transform_noise_coordinate_2d(state, &x, &y)

    #partial switch (state.fractal_type)
    {
    case:
        return gen_noise_single_2d(state, state.seed, x, y)
    case .FBM:
        return gen_fractal_fbm_2d(state, x, y)
    case .Ridged:
        return gen_fractal_ridged_2d(state, x, y)
    case .Ping_Pong:
        return gen_fractal_ping_pong_2d(state, x, y)
    }
}

get_noise_3d :: proc (state: FNL_State, x, y, z: FNL_Float) -> f32 {
    x := x; y := y; z := z
    transform_noise_coordinate_3d(state, &x, &y, &z)

    // Select a noise type
    #partial switch (state.fractal_type)
    {
    case:
        return gen_noise_single_3d(state, state.seed, x, y, z)
    case .FBM:
        return gen_fractal_fbm_3d(state, x, y, z)
    case .Ridged:
        return gen_fractal_ridged_3d(state, x, y, z)
    case .Ping_Pong:
        return gen_fractal_ping_pong_3d(state, x, y, z)
    }
}

domain_warp_2d :: proc(state: FNL_State, x, y: ^FNL_Float) {
    #partial switch (state.fractal_type)
    {
    case:
        domain_warp_single_2d(state, x, y)
    case .Domain_Warp_Progressive:
        domain_warp_fractal_progressive_2d(state, x, y)
    case .Domain_Warp_Independent:
        domain_warp_fractal_independent_2d(state, x, y)
    }
}

domain_warp_3d :: proc(state: FNL_State, x, y, z: ^FNL_Float) {
    #partial switch (state.fractal_type)
    {
    case:
        domain_warp_single_3d(state, x, y, z)
    case .Domain_Warp_Progressive:
        domain_warp_fractal_progressive_3d(state, x, y, z)
    case .Domain_Warp_Independent:
        domain_warp_fractal_independent_3d(state, x, y, z)
    }
}